Bio Exam 1 Flashcards
What are the specialities of biopsychology?
Physiological psychology Psychopharmacology Neuropsychology Psychophysiology Cognitive Neuroscience
What is physiological psychology?
Direct manipulation of brain in animal research; focuses more on theory rather than immediate practical application.
What is Psychopharmacology?
Manipulation of neural systems and bx with drugs; animals and humans
What is Neuropsychology?
Cognitive & psychological effects of brain damage in human patients Clinical app of brain behavior concepts. Testing of cog abilities, gathering info from other sources and consolidating.
What is Psychophysiology?
Relationship between physiological activity and psychological processes in humans (EEG) Biofeedback—heart rate, muscle tension, skin temp, etc. Using biofeedback ppl can control their physiological responses
What Cognitive Neuroscience?
Brain basis for cognitive / emotional behavior(PET Scan, fMRI)
Who is Dr. Egas Moniz and why is he significant in Neuropsych?
Portuguese neurologist attended a conference in 1935, which resulted in him developing the prefrontal lobotomy.
What were the initial findings of the prefrontal lobotomy?
A patient who had removal of prefrontal lobes during tumor resection showed no intellectual impairment – IQ scores remained the same post surgery
Why were prefrontal lobotomies discontinued?
Even tho IQ scores didn’t change, behavioral changes did. Neuropsych tests showed there were impairments. Apathy, couldn’t feel emotions, or demonstrate affect, passive, indifferent. Apathy was so extreme they needed daily supervision to get through a routine.
What are dichotomous traits?
Present in one form or another but never in combination e.g. pea color
What are true breeding lines?
Interbred members always produce offspring with the same trait E.i. brown pea parents produce brown pea children- white pea parents produce white pea children.
What did Mendela find when he interbred brown and white peas?
He found that demonstrated traits not expressed by parents could be passed on to children (First generation offspring all had brown peas – Dominant trait Second generation offspring were 75% brown and 25% white – white was recessive trait)
What is a phenotype?
The organism’s observable traits – the expression of the trait on the outside
What is a genotype?
The traits that can be passed on to children thru genetic material – underlying genetic make up
What were the 4 ideas Mendel proposed?
- Two kinds of inherited factors for each dichotomous trait – now referred to as genes. 2. Each organism possesses two genes for each of its dichotomous traits 3. One of the genes in a heterozygous pair dominates the other in expression of the trait 4. For each trait, a child randomly inherits one of the father’s two genes and one of the mother’s two genes
What are alleles?
Two genes that control the same trait are called
What are homozygous genes?
Identical genes
What are heterozygous genes?
Two different genes
Where are genes located?
On chromosomes in the nucleus of the cells
How many chromosomes do humans have?
46 chromosomes arranged in 23 pairs
What are autosomes?
The 22 pairs of chromosomes that are NOT the sex chromosomes
Where are the two genes (alleles) that control a trait located?
At the same locus, one on each chromosome of a particular pair
What is Meiosis?
Process of cell division that produces gametes (i.e. sperm and egg)
What are the phases of meiosis (generally)?
- Chromosomes divide and one of the pair goes to one gamete and the other of the pair goes to the other gamete - Each gamete contains only half the usual number of chromosomes i.e. 23 instead of 46 - Union of sperm and egg combines these two sets of 23 chromosomes to produce 46
How many possibilities are there for gamete combinations?
Approximately 8.3 million
What is mitosis?
All cell growth that occurs after Meiosis
What is genetic recombination?
During early stages of meiosis, chromosomes overlap or crossover one another and break apart at the points of contact, exchanging sections of chromosome. The chromosomes are not passed on in tact – it’s a splice of both members of the pair. This increases the potential combination of chromosomes
What results happen from genetic recombination?
- Parents rarely pass on intact chromosomal clusters of genes to children 2. Each gamete contains chromosomes that are unique spliced together combinations inherited from your father and mother 3. Crossover rarely occurs between adjacent genes and frequently between genes at opposite ends of chromosome
What are the two different types of sex related genes?
XX for females XY for males
What are sex-linked traits?
Traits influenced by genes on a sex chromosome (traits conveyed on the sex chromosome)
What chromosome controls almost all sex-linked traits and why?
The X chromosome because Y is smaller and carries fewer genes (mostly just carries the ones determining male sex development)
True or false: traits controlled by genes on the X chromosome occur in one sex more often than the other
true
True or false: recessive traits occur more often in females than males
False; dominate traits occur more often in females than males because they have twice the chance of inheriting the dominate gene
Why do recessive sex-linked traits occur more in males?
If they inherit the trait on X, there is nothing to over-ride it on Y and they express the trait, whereas in females they will express it only if they inherit two recessive genes Ex: Color blindness is recessive sex-linked trait and is rare in women
Each strand of DNA is composed of what?
Nucleotides bases
What are the 4 nucleotides?
Adenine Thymine Guanine Cytosine
What determines the genetic code?
The sequence of the nucleotide bases
What nucleotides attract to each other?
- Adenine attracts to thymine - Guanine attracts to cytosine
What happens in replication?
The helix unravels and loose nucleotides are attracted to the unpaired strands and form two identical chromosomes
What are structural genes?
They are the most prevalent They contain information necessary for synthesis of proteins
What are proteins?
Long chains of amino acids that control physiological activities of cells and are important components of their structure
True or False: All cells in the body (brain, hair, bone, etc.) do not contain exactly the same set of structural genes.
False, they do contain exactly the same set of structural genes
What are enhancers?
- Sections of DNA that control structural genes and whether or not they initiate synthesis of protein - If protein is synthesized the gene is expressed – no protein synthesis, gene is not expressed.
How do enhancers work?
Enhancers work like switches, they can increase or decrease the extent to which a structural gene is expressed.
What are transcription factors?
- Proteins that bind to DNA and regulate genetic expression - Many of these binding proteins that influence enhancers are influenced by signals received from the cell as it responds to the environment - Thus providing the mechanism for interaction of the environment and genes to influence development - Even if there was a perfect transcription and translation there can still be abnormalities
What is the process for the expression of a gene?
- Enhancer/promoter genes initiate process 2. DNA for the section of structural gene unravels 3. exposed DNA attracts messenger RNA (mRNA) which forms a strand until reaching another enhancer/promoter gene that signals the end of the structural gene 4. mRNA then goes to a ribosome in the cytoplasm of the cell 5. ribosome moves along the mRNA and transcribes the genetic code 6. each group of 3 consecutive nucleotides is called a codon - codon instructs the ribosome which of 20 amino acids to add to the protein it is constructing 7. as ribosome reads mRNA it attracts transfer RNA attached to an amino acid 8. ribosome reads codon after codon and adds amino acid after amino acid until it reaches another enhancer/promoter gene that signals the end of the structural gene 9. the completed protein is then released into the cytoplasm
What is the difference in the nucleotides between mRNA and DNA?
- mRNA is the same as DNA except it has uracil instead of thymine
What is the Human Genome Project (HGP)?
Allowed us to map the entire genetic blueprint of a human being, to ultimately build another human being
What are loci?
-Composed of hundreds/thousands of nucleotide bases.
How many nucleotide bases (A, C, T, and G) does the human genome contain?
-3.1 billion nucleotide bases
How many nucleotide bases does the average gene contain?
-Roughly 3,000 nucleotide bases
What is the largest known human gene (comprised of the single most nucleotide bases)?
Dystrophin (don’t need to know, but dystrophin definition = a protein found in skeletal muscle, which is absent in sufferers from muscular dystrophy.)
What percentage of our genes are structural genes (that code for protein)?
1%
What percentage of functions of discovered genes are unknown ?
Over 50%
What is Single Nucleotide Polymorphism (SNP)?
About 1.4 million locations where single-base DNA differences occur in humans (used to find chromosomal locations for disease associated sequences).
What are 3 Epigenetic factors that influence genetic expression?
1) Non-gene DNA 2) Small RNA molecules 3) DNA Methylation and Histone remodeling
Genes make up about 1% of human genome, while the rest are called:
Non-gene DNA
What does Nongene DNA do?
Influences the expression of nearby genes
What is the main role of Small RNA Molecules?
To regulate gene expression
What are 4 main genetic influences?
1.) Not only structural genes 2.) Interaction of many structural genes 3.) Influence of epigenetic factors 4.) Developmental timing of expression of particular genes in specific brain structures
What does the big picture of the structure of a cell look like?
>Cell >Chromosomes >DNA strand/molecule (double helix) >Genes (adenine & thymine, guanine & cytosine) >Proteins
What is Epigenetics?
Other moderating factors that influence the way genes are expressed (rather than the genes themselves)
What is RNA editing?
- Cleave or splice mRNA to form new base sequence - Once messenger RNA transcribed the protein, therefore the expression of the gene is altered
What are some basic tenets DNA Methylation and Histone remodeling?
-Methylation causes Histone molecule to change it’s shape, which effects DNA expression -Can be induced by experience: neural activity, hormonal change -Changes can last a lifetime and be passed on genetically
What is Down Syndrome?
Trisomy 21 (extra chromosome on #21; supposed to be 2, but has 3)
Is there one specific gene (APOE-E4) that creates Alzheimers?
No. APOE-E4 does not create Alzheimers. But, about 2/3 of ppl with alzheimers will have APOE-E4, and about 2/3 of ppl with the gene APOE-E4 will have alzheimers.
True or False: Genes help metabolize fatty acids?
True
True or False: Breastfeeding increases IQ?
-It depends :) - It depends on many things; allele, environment, etc. -Dull rats worse than bright rats only if raised in impoverished environment -Genetics CAN always be mediated by environment (getting hit by max doesn’t matter how many or what genes you have); our environment CAN’T always be mediated by our genes.
What is one of the main points of genetic research methods?
To attempt to demonstrate the linkage between genes and bx.
True or False: Identical (MZ) twins share only 90% of their genes?
False. They share 100% of their genes.
True or False: Fraternal twins (DZ) share a bout 50% of their genes?
True
What is a Concordance Rate?
It examines the likelihood of whether a twin shares a behavioral trait with the other twin
What are some examples of genetic influences on human bx?
1.) Down Syndrome 2.) Huntington’s Dz 3.) Duchenne Muscular Dystrophy (recessive X-linked abnormality; effects primarily boys) 4.) Fragile X (most common form of inherited intellectual disability in boys; portion of X chromosome is repeated)
In the MN Twin Study, Schizophrenia was 4x higher in MZ twins than DZ twins, and MZ twins raised together had an IQ correlation of .80, and .75 for those raised apart. What does this mean?
Differences between individuals’ I.Q. and expression of schizophrenia has a genetic influence.
What is the Heritability Estimate (H.E.)?
-It tells us about the contribution of genetic differences to phenotypic differences among subjects – i.e. in the population or in a group of ppl. -H.E. says nothing about the relative contribution of genetics and experience to the development of an individual.
True or False: There is a difference in heritability of IQ in 7-yr-old twins with very low SES and high SES?
True. Heritability near 0 for very low SES, and Heritability near 1.0 for high SES
True or False: Found in a Epigenetic twin study of MZ twins over time, their epigenetics were indistinguishable early in life but they accumulated differences over time and eventually each tissue type showed a different epigenetic profile?
TRUE! Oofta.
What are 2 main points of Epigenetic twin studies implications?
1.) Different epigenetic rates for MZ twins may account for why one twin develops a disease and the other doesn’t. 2.) Disease discordant MZ twin studies may reveal epigenetic factors that contribute to the disease.
Neurons contain what three usual structures?
Soma Dendrites Axon
What does the Soma or cell body contain?
The nucleus and much of the machinery that operates the cell
What is the Dendrites purpose?
Receives information from other neurons, can grow and form new connections.
Describe an Axon
It looks like the tail of the neuron, typically protected by the myelin sheath. It can grow and form new connections. Nerves are composed of many axons surrounded by tough elastic connective membranes.
What are the nodes that are found on the Myelin Sheath? Describe them
Nodes of Ranvier, they are the gaps that can be found on the myelin sheath. It serves to facilitate the rapid conduction of nerve impulses
What is the Myelin Sheath’s function?
To increase the speed of impulses. Waves vs hopping. Unmyelinated nerves conduction happens in waves vs myelinated ones where they hop around and go faster.
The place where action potential originates.
Axon Hillock
What is the function of the Terminal Button?
Forms synapses with dendrites, soma or axons of other neurons, also secretes transmitter substances
What is classified dependent on structure? Name their classifications. (3)
Neurons Multipolar Bipolar Unipolar
Multipolar, bipolar, and unipolar neurons get their name depending on what?
How many stalks are available.
Neuron are classified according to function as well. What are the three functions?
Sensory Motor Interneurons
What is a sensory Neuron?
A neuron that transmits sensory information (sight, sound, feeling, etc.). They are activated by sensory input, and send projections to other elements of the nervous system, ultimately conveying sensory information to the brain or spinal cord.
What is a motor neuron?
It leaves the brain and elicits some sort of physical response
What is an interneuron?
It enables communication between the sensory neurons or motor neurons to the central nervous system. (responsible for perceptions, planning execution, simple functional scheme)
Name all 8 internal components of a neuron.
- membrane 2. nucleus 3. nucleolus 4. ribosome 5. mitochondria 6. Endoplasmic reticulum (some are rough others smooth) 7. Golgi Apparatus 8. Microtubules/filaments
What is the membrane’s function in the neuron?
It’s a double layer of lipid molecules (fat) It is embedded with a variety of protein molecules that perform various functions such as detecting and passing information about substances outside other cells. Controls what comes in and out of the cell. Actively transports material in and out of cell.
What contains chromosomes and nucleolus?
The Nucleus
What internal component produces ribosomes?
The nucleolus
This internal component in the cytoplasm decodes mRNA for formation of proteins used in the neuron. What is it?
Ribosome
This internal component of the neuron is known as the power house and it is responsible for converting glucose to ATP and stores CA. It also contains DNA from only the mother, unlike other cells.
Mitochondria
Name the system of tubes for storage and transport of material within the cells and is important for protein synthesis.
Endoplasmic reticulum
Endoplasmic reticulum there are two types of tubes. What are they and how are they different from each other?
Rough and smooth tubes. Rough tubes contain ribosomes that produces proteins are transported out of the cell or used in the membrane. Smooth tubes are responsible for transporting and storing molecules.
Golgi Apparatus, how does it organize and clean the neuron?
-packages proteins including neurontransmitters into vesicles (organize) -produces lysosomes which break down substances no longer needed by the neuron. (clean)
What are the microtubules/filaments function?
Transports substances between cell body and distal cell/terminal button.
Name the 5 System support cells.
- Glia 2. Astrocytes 3. Oligodendrocytes 4. Microglia 5. Schwann Cells
Because Neurons have such high metabolism and cannot store energy they need the Glia for what purpose?
To supply the neuron with constant sources of nutrients (glucose and oxygen) and will die within minutes if it is interrupted. (life support)
One Astrocyte cell will have how many connections with other neurons?
Many
What do Astrocytes provide for neuron?
Provide physical support, remove debris and transport nutrients to neurons
What provides physical support and forms the myelin sheath around axons in the brain?
Oligondendroglia
Which support cell is involved in phagocytosis and brain immune function?
Microglia
What is phagocytosis?
Digesting of dead neurons
Schwann Cells are myelin that wraps around one axon in what system? (PNS, CNS, ANS)
Peripheral nervous system
What is the function of blood-brain barriers?
Alls for free movement of most substances between plasma and extracellular fluid
How does the BBB (blood brain barrier) act in the Central Nervous System?
Walls are not permeable for the most part, substances are actively transports of proteins between capillary and neuron.
Where is the BBB not as strong and for what reason?
Throughout the brain in the area that controls vomiting so that it can get rid of poisons and other toxins that may interfere with proper brain functioning.
Generally, the resting potential inside of an axon is
-70mV
In order to depolarize the membrane of an axon (leading to either sub-threshold and threshold stimulation) the following must occur where?
The inside of the axon must be stimulated by positively charged ions.
True or False: action potential is an all or nothing principle?
True
True or False: action potential decreases in mV as it is propagated down the membrane of an axon.
False, it stays the same in mV as is propagated down the membrane of an axon.
What happens when electrolytes are dissolved in water?
They split apart into two particles, each with an opposing electrical charge
Electrolytes are a product of what kind of force?
Electrostatic force
What is the force that pulls sodium ions from an area of high concentration to an area of low concentration?
Diffusion
What three things are true of Sodium?
It is a positively charged ion concentrated outside of the neuron It is attracted to the inside of the ion due to diffusion AND the electrostatic force. It can only enter the neuron by sodium-potassium transporters.
Which is a negatively charged ion that is highly concentrated outside of the neuron and is pushed into the neuron via diffusion, but out of the neuron via the electrostatic force?
Chloride
What are some characteristics of potassium in the brain?
It’s highly concentrated inside the neuron It’s pulled into the neuron by electrostatic force
What happens when action potential is reached?
Sodium and Potassium channels may open on the neuron of the neuron. The membrane potential depolarizes
What are some characteristics of potassium channels?
They require more depolarization of the membrane to open. They carry Potassium out of the cell due to diffusion AND the electrostatic force They close when membrane potential begins to return to normal
True or false: After the cell reaches action potential, Potassium becomes concentrated outside of the cell, which causes the membrane to “overshoot” and become hyperpolarized (i.e. charge goes below -70mV).
True
What happens after a neuron has reached action potential to restore ion concentrations inside and outside of the cell?
Sodium-Potassium transporters remove Na+ from the inside of the cell and retrieve K+ ions.
True or false: Sodium-Potassium transporters are crucial for restoring Na+ and K+ levels to normal after reaching action potential.
False: The amount of these ions that cross the membrane are miniscule relative to the overall concentrations. Transporters are important for the neurons functioning over the long-term because too much Na+ in the neuron would prevent neuron functioning over time.
True or false: Sub-threshold electrical impulses causes no change in the cell because action potential was not reached.
False: sub-threshold electrical impulses produce a disturbance in the neuron membrane, which changes the electrical charge of the membrane, that becomes smaller as it moves away from the point of stimulation.
True or false: Passive conduction is slower than active conduction.
False: passive conduction (i.e. does not change membrane permeability) is faster than active conduction because passive conduction conserves energy.
In myelinated axons, action potential occurs where?
At the Nodes of Ranvier
What happens when an axon splits into two?
Action potential of the same magnitude is conducted down both axons
What are the three parts of the synapse?
Presynaptic membrane (terminal button) Postsynaptic membrane (on a dendrite) Synaptic cleft
A _____________ is any transmitter substance that attaches to a binding site.
Ligand
True or false: Transmitter substances will attach to any binding site, regardless of its type.
False; transmitter substances will attach only to binding sites specific for it. The binding site will accept and be activated only by a transmitter substance that it is specific for and is specific for it
About how big is the gap between pre- and postsynaptic membranes?
25 nanometers
Synaptic vesicles contain _____________.
neurotransmitters
Which substance directly causes the vesicles to merge with the presynaptic membrane?
calcium ions (CA++)
True or false: Synaptic vesicles are generated inside the soma and transported to the terminal button via microtubules.
True
True or false: Before the action potential reaches the terminal button, CA++ is more highly concentrated within than without the neuron.
False; CA++ is more highly concentrated outside the neuron before the action reaches the terminal button
Where are the synaptic vesicles located?
In the terminal buttons
Both diffusion and electrostatic forces cause CA++ to move once the calcium channels are open.
True
After vesicles have deposited their contents at the presynaptic membrane, they do which of the following?
They merge with the wall and recycle themselves They close up, but stay connected with the wall They close up, and move back into the terminal button to be refilled
The opening of which of the following ion-specific channels result(s) in an inhibitory postsynaptic potential (IPSP)?
Chloride (Cl-) Potassium (K+)
Which substance activates enzymes involved in structural changes of neurons?
Calcium (CA++)
What is another word for the resting membrane potential?
Polarized (-70mV)
What happens when action potential arises?
It depolarizes the membrane
When the action potential bounces back and goes more negatively charged, it is called what?
Hyperpolarization (decreases the chances of action potential being achieved)
Substances that bind directly to postsynaptic receptors, thereby causing channels to open, are called _____.
Neurotransmitters
Which type of postsynaptic receptor indirectly alters ion channels?
Metabotropic
Metabotropic receptors may lead to the utilization of which of the following substances in opening ion channels?
The alpha subunit of G proteins Enzymes Second messengers
What substance travels to the nucleus of neurons and can affect gene expression?
Second messengers
The most common way neurotransmitters are deactivated is ___________.
Reuptake
True or false: Enzymatic deactivation allows neurotransmitters to be reused.
False
The term that refers to the summation of postsynaptic potentials (PSPs) is called __________.
neural integration
_________ functions to deactivate neurotransmitters.
acetycholinesterase
_________ refers to the remnants of synaptic vesicles along the presynaptic membrane after they have released their contents.
omega figures
When autoreceptors are not activated, the production and release of neurotransmitters __________.
increases
What type of structure is formed when the terminal button of one neuron comes into contact with the terminal button of another neuron?
axoaxonic synapse
What two things influence the amount of neurotransmitter released?
autoreceptor inhibitory postsynaptic potential
True or false: One function of inhibitory synaptic connections is to increase behavior.
True
What transmitter substances can affect areas not in direct contact with a neuron’s terminal button?
neuromodulators hormones
__________ cells have receptors for hormones, which can affect their functioning.
target
What are two characteristics of peptides?
Stimulate metabotropic receptors in the postsynaptic membrane Are insulin and pituitary hormones
What are four characteristics of steroids?
They are sex and adrenal hormones They direct chromosomes to initiate protein synthesis They pass through membranes to bind with receptors in the nucleus They are a lipid
Where are hormone receptors located?
On a membrane or nucleus
What are neurotransmitter substances and what do they do?
They are chemicals produced by the body that communicate between neurons i.e. across synapses
What is a neuraxis?
An imaginary line drawn through the spinal cord up to the front of the brain.
Anatomical directions are understood relative to the Neuraxis (T or F)
True
Rostral means the same as what other term?
Anterior
What does anterior (rostral) mean in regards to anatomical direction?
toward the head
What does Posterior (caudal) mean in regards to anatomical direction?
toward the tail
What is the anatomical direction that is toward the belly?
Ventral (inferior)
What is the anatomical direction that is toward the back (top of head)?
dorsal (superior)
what is the term indicating that it pertains more to the middle line of the body?
Medial
Term signifying to the side.
lateral
Which term means towards the center?
afferent
What does efferent mean?
away from the center
What does the term Ipsilateral mean?
the same side of the brain
What is the term that signifies the opposite side of the brain?
contralateral
What are the three planes in which the brain can be sectioned into?
Sagittal Coronal/frontal/transverse horizontal
Describe a sagittal plane dissection.
vertical cut, dividing brain into left and right regions
Describe a Coronal/frontal/transverse plane dissection.
vertical cut, dividing brain into front and back regions
Describe a Horizontal plane dissection
horizontal cut, dividing brain into top and bottom regions
Which nervous system is comprised of the brain and spinal cord?
central nervous system
The peripheral nervous system is comprised of what two elements?
cranial/spinal nerves peripheral ganglia
Afferent PNS nerves carry sensory information where?
the brain
Name the PNS nerves that project to target organs and to muscles.
Efferent PNS nerves
What percentage of blood volume is continuously being supplied to the brain?
20 percent.
Does the percentage of blood volume change depending on blood flow needed by other body parts and the activities of other systems?
no
Because the brain cannot store fuel (glucose) what does it require to extract glucose?
O^2
What will happen to the brain if it goes 5 minutes without blood (O2 and glucose)?
suffer permanent damage
What is the name of the tough protective membrane surrounding the brain and spinal cord?
Meninges
What is the name of the outer thicker layer of meninges that is the toughest
Dura Mater
Arachnoid is what layer in the meninges?
the middle layer
What is the name of the layer of the meninges that is soft and contains smaller surface blood vessels?
Pia matter
Name the space between the arachnoid and pia. What does it contain?
subarachnoid space which contains cerebral fluid
Approximately how much does the brain weigh?
3 pounds or 1400 g
Describe the brains texture.
soft, jelly like and delicate
What is the purpose of the Cerebrospinal Fluid?
it reduces the brains weight to 80g or approximately 3 oz helps protect the brain from shock
In how many ventricles can Cerebrospinal fluid be found?
4
What is the purpose of the choroid plexus?
to produce cerebrospinal fluid in each ventricle
How does choroid plexus produce cerebrospinal fluid?
it extracts CSF from blood.
What is Cerebrospinal fluid’s half life?
3 hours
Where does cerebrospinal fluid drain into and where does it go?
drains into superior sagittal sinus and then goes into the veinous system.
What makes up the Central Nervous system?
Brain and spinal cord
What is one reason why brain areas control different types of functioning?
The types of input that particular parts of the brain receive from the neurons connected to them are unique
What happens if part of an animal’s brain is removed before neurons connect with the cortex?
All usual functional areas are still represented, but “squeezed” into the remaining cortex, e.g., reconnecting visual pathways to the temporal lobe.
True or False: Experience affects how brain functioning develops?
True
What is some proof that experience affects how brain functioning develops?
amputation: cortex eventually processes input from adjacent body areas musicians: larger cortical area processes sensory input for left hand blind people who read Braille: larger area of brain activated when touching something with fingers language development in children
What is the gyrus?
The ridge between two clefts on the cerebral surface in the brain (i.e., a bulge, wrinkle, high ground)
What is a sulcus?
A groove/crack on the surface of the brain - more of a superficial crack
What is a fissure?
A groove/crack on the surface of the brain - deeper than a sulcus
How much of the cortex is in the sulci & fissures?
Two-thirds
What is the advantage of having sulci & fissures in the brain?
It allows for 3 times the amount of surface area
What is white matter?
Pathways/tracks of axons (white b/c of myelin)
What is grey matter?
High congregation of neuron cell bodies (creates the darker pigment)
Where is the central sulcus/fissure?
It is down the center of the brain (along the frontal/coronal/transverse plane), dividing the Frontal Lobe (anterior) and the Parietal Lobe (posterior)
Where is the superior longitudinal fissure?
Goes the long way of the brain (along the sagittal plane) separating the right and left hemispheres
Where is the lateral/Sylvian fissure?
Boundary between the Frontal and Temporal Lobes and Temporal and Parietal Lobes (mostly along the horizontal plane)
Where is the frontal lobe, and what are some of its main functions?
Front of the brain, go figure; planning/executing and movement
Where is the temporal lobe and what is one of its main functions?
Beneath the lateral/Sylvian fissure on both cerebral hemispheres; hearing
Where is the parietal lobe and what is one of its main functions?
Near the center of the brain, behind the frontal lobe and the central sulcus/fissure; integrating sensory information into perception
Where is the occipital lobe and what is one of its main functions?
The bottom back part of the cortex; vision
What does the posterior part of the brain do and which cortices are responsible for this function?
It mediates sensory processing (w/ contralateral representation); primary visual cortex, primary auditory cortex, and primary somatosensory cortex
What does the anterior part of the brain do and which cortices are responsible for these functions?
It controls movement (contra-laterally) and is responsible for executing “something” (not just executive functioning); premotor cortex, primary motor cortex, and prefrontal cortex
What are the three levels of processing information?
Primary Secondary (association areas) Tertiary (multimodal areas)
What is the primary visual cortex?
The part of the neocortex that receives visual input from the retina
What is the primary auditory cortex?
The area of the brain that dispenses sound and is responsible for the ability to hear.
What is the primary somatosensory cortex?
It is the main sensory receptive area for touch. It is located in the lateral fissure
What is the primary motor cortex?
One of the principle areas involved in motor function; generates neural impulses that control the execution of movement
What is contralateral representation?
One side of the brain will control the opposite side of the body
What is bilateral representation?
Both sides of the brain control something.
What is the dividing demarcation between the frontal and parietal lobes (motor and sensory functions)?
The central sulcus/fissure
What is the function of the posterior association areas?
perceiving and learning; where visual, auditory, and somatosensory association areas meet; receives info from primary sensory areas to form perception and store memories
What are 2 anterior association areas and what are their functions?
premotor area (controls patterns of movement and transmits input to primary motor area) prefrontal area (planning, regulation, strategy formation, execution of action)
What are multimodal association areas (MMAAs), what are the 3 general categories of MMAAs, and what do they do?
They are an integration of multiple sensory modalities in one area of the brain. We have anterior, posterior, and limbic association areas. When Michael refers to MMAAs, most of the time he’s referring to the posterior association area (PAA) exclusively (b/c this is where visual, auditory, and touch info gets integrated and sent off to the prefrontal area for decisions to be made). MMAAs involve the highest levels of integration, assimilation, complex understanding, & cognitive processing.
Where are the MMAAs?
The area they cover is the same as that covered by the combination of anterior, posterior, and limbic association areas (i.e., much of the prefrontal and temporal cortices and some of the parietal cortex).
Where is the MMAA that Michael refers to most often (i.e., posterior association area)?
On top of the lateral sulcus - where the temporal, parietal, and occipital lobe meet
What does the premotor area do?
It controls patterns of movement and transmits input to primary motor area. It houses the memorized actions for movement; it starts the process to do purposeful action.
Where is the premotor cortex?
Behind (Caudal/Posterior) the Prefrontal Cortex and in front of (Rostral/Anterior) the Primary Motor Cortex
Where is the somatosensory association cortex?
Behind (Caudal/Posterior) the Primary Motor Cortex and Primary Somatosensory Cortex and in front of (Rostral/Anterior) / underneath (Ventral/Inferior) the Parietal Lobe
Where is the visual association cortex?
Behind (Caudal/Posterior) / underneath (Ventral/Inferior) the Parietal Lobe and on top of (Dorsal/Superior) / in front of (Rostral/Anterior) the Primary Visual Cortex
Where does information flow to first?
The primary sensory areas used for sensory detection (registers & processes most elemental info, e.g., lines & light)
Where does information go after the primary sensory area?
The info that was processed in the primary sensory areas are then sent to sensory association areas for further processing of information
What is the job of the sensory association areas?
To integrate those individual dimensions of sensory detection into a perception. This is where you perceive visual images object, recognize sound and tactile input. Where you figure out the difference between just a line and a table.
What is “lateralization of function?”
Left and right sides do not process info in the same way and do not process the same aspects of information
What does the left hemisphere process?
Analysis of information, serial processing of and controlling events in sequence. Good for language, math.
What does the right hemisphere process?
Synthesis of information, integrating multiple elements into a whole, visual-perceptual processing. Good for visual/spatial operations because of how it synthesizes info.
True or false: because of lateralized functions, we perceive experience as fragmented.
False; we perceive experience as seamless. We are unaware of unique processing of each hemisphere
What is the corpus callosum?
A commissure; A broad band of nerve fibers that join the two hemispheres of the brain.
What is the neocortex?
The outer covering of the brain.
What are the 4 major structures in limbic system?
cingulate cortex, hippocampus, amygdala, mammillary bodies
What is the cingulate cortex?
a strip of limbic cortex lying along the lateral walls of the groove separating the cerebral hemispheres, just above the corpus callosum
What is the function of the hippocampus?
critical for forming new memories and learning
What is the function of the amygdala?
negative emotional processing; i.e., expression of emotions, emotional memories, and recognition of signs of emotions in other people; specifically, assigning negative valence to perception and memories of negative events for the purpose of learning
What are mammillary bodies?
protrusions of the bottom of the brain at the posterior end of the hypothalamus, containing some hypothalamic nuclei; part of the limbic system important in memory
What causes Wernicke-Korsakoff syndrome (WKS)?
WKS primarily shows up in alcoholics, resulting from thiamine (vitamin B1) deficiency
Which brain structure(s) is/are primarily affected by WKS?
associated with atrophy of the mammillary bodies
What are some symptoms of WKS?
vision change, ataxia (unstable gait), and impaired memory
What is the fornix and what is its purpose?
fiber bundle (of axons) that connects the hippocampus with mammillary bodies; part of the limbic system
What are the 3 major structures that comprise the basal ganglia?
globus pallidus, caudate nucleus, putamen
What are the basal ganglia and what is their function?
a collection of subcortical nuclei that regulate motor functions and movements; are involved in the process of becoming more skilled at performing a practiced movement
Which diseases involve dysfunction of the basal ganglia?
Parkinson’s and Huntington’s
What are some symptoms of Parkinson’s disease?
weakness, tremors, rigidity of the limbs, poor balance, difficulty initiating movements
Which brain structures/systems belong within the telencephalon category?
cerebral cortex, limbic system, basal ganglia
Describe the structure of the thalamus.
2 symmetrical lobes (right and left)
What comprise the thalamus and what is their basic function?
nuclei receive sensory information and transmit it to the cortex
Which brain structures/systems belong within the diencephalon category?
thalamus and hypothalamus
What are the major functions of the hypothalamus?
regulation of the autonomic nervous system (ANS), control of major parts of the endocrine system, and integration of species-specific behaviors
What are the 2 structures of the endocrine system most affected by the hypothalamus?
anterior pituitary and posterior pituitary glands
How does the hypothalamus interact with the anterior pituitary gland?
hormones from the hypothalamus get secreted into blood vessels that connect to the anterior pituitary gland (APG), which causes the APG itself to secrete hormones, which in turn (in many cases) cause other endocrine glands to secrete hormones; e.g., gonadotropin from APG causes release of gonadotropic hormones involved in reproduction
How does the hypothalamus interact with the posterior pituitary gland?
axons from the hypothalamus terminate in the posterior pituitary gland (PPG) and release hormones into the bloodstream; e.g., PPG releases vasopressin, which regulates kidney output
What are the 2 major structures that make up the tectum?
superior colliculus and inferior colliculus
Which activities are mediated by the superior colliculus?
visual orienting and head turning
What activity is mediated by the inferior colliculus?
auditory processing
Which brain structures/systems belong within the mesencephalon category?
tectum and tegmentum
What are the 4 major parts that comprise the tegmentum?
reticular formation, periaqueductal gray, substantia nigra, and red nucleus
Where does the reticular formation project sensory input?
cortex, thalamus, and spinal cord
What roles does the reticular formation play in the human body?
arousal, sleep, muscle tone, and movement (primarily first one)
Where is the periaqueductal gray located?
surrounding the cerebral aqueduct
What are the functions of the nuclei in the periaqueductal gray?
control of movement, inhibition of pain perception, and species-typical behaviors (e.g., fighting and mating)
What is the red nucleus and what does it do?
a large nucleus of the midbrain that receives inputs from the cerebellum and motor cortex and sends axons to motor neurons in the spinal cord
Where does the substantia nigra project sensory input?
caudate and putamen
What is the substantia nigra and what role does it have in the human body?
a darkly stained region of the tegmentum that contains neurons that communicate with the caudate nucleus and putamen in the basal ganglia (i.e., motor control)
Which disease involves deterioration of the substantia nigra?
Parkinson’s
The Metencephalon consists of
The Pons and the Cerebellum
What 5 types of input does the cerebellum receive?
Visual, Auditory, Vestibular, Somatosensory, and Muscle Movement
After the cerebellum integrates the input it receives, what effect does it have on the human body’s movement?
It has a smoothing and coordinating effect on movement
In terms of movement, what is the cerebellum especially important for?
rapid, sequenced movements
The cerebellum has more neurons than
the cortex
The Pons contains the core of which brain structure?
reticular formation
The pons is involved in which two states of being in the human body?
Sleep and Arousal
Which brain structure contains some connections that have to do with dreaming?
The Pons
Which brain structure in the brainstem relays information from the cortex to the cerebellum?
The Pons
The Medulla contains part of which brain structure?
the reticular formation
What are three examples of vital functions that the nuclei of the medulla control?
Regulation of the cardiovascular system, breathing, and skeletal muscle tone (much damage here can be deadly! Eek!!)
Name the groups of Vertebrae in the Spinal Cord from top to bottom
Cervical (8 levels), Thoracic (12 levels), Lumbar (5 levels), Sacral (5 levels), and Coccygeal (1 level)
Name the three primary functions of the spinal cord.
transmission of information from the brain to control motor movements and body functions, Transmission of sensory information from sense receptors to the brain, and controlling reflexes.
At which levels of the spinal cord do spinal nerves exist?
at all levels of the spine
How many spinal nerves exist at each level of the spine?
2
Which two roots join together to become spinal nerves?
a Dorsal (posterior) roots and a Ventral (anterior) root
Name 3 steps that are involved in the formation of spinal nerves
Small bundles of fibers emerge from dorsal and ventral surface of the spinal cord, groups of nerves fuse together and become dorsal and ventral roots, the dorsal and ventral roots join to become spinal nerves.
What is the role of the somatic part of the peripheral nervous system?
It is involved in transmitting sensory and motor information to and from brain. (It mediates motor and sensory processes that you have conscious awareness of)
True or False: The somatic nervous system is effective through spinal nerves and cranial nerves.
True.
True or False: Spinal nerves exit the spinal chord only at one specific site?
False. Spinal nerves exit all along the spinal chord (both sides, R & L).
Where do cranial nerves exit, and what is their function?
Cranial nerves exit through the brain stem, before the spinal chord. They have the same function as spinal nerves (control sensory and motor functions), but do so in the brain (head and neck area), except for #10 (the Vegas nerve), which innervates the visceral organs. There are 12 different pairs of cranial nerves (R & L, 1 for each side of spinal column; don’t need to know each specifically though)
Describe what cell bodies of efferent neurons are and what they do.
Axons that transmit info from the brain to muscles and glands. They’re located in the gray matter of spinal cord and exit spinal cord through ventral root.
Describe what cell bodies from afferent neurons are and what they do.
Axons that transmit sensory info from somatosensory receptors to spinal cord. They’re located outside CNS in dorsal root ganglion (except visual) and enter spinal cord through dorsal root.
Describe a nerve & where it’s located.
A collection of axons; outside CNS.
Describe a tract & where it’s located.
A pathway; collection of axons; inside CNS.
Describe a nucleus & where it’s located.
A collection of cell bodies; inside CNS.
Describe a ganglion & where it’s located.
A collection of cell bodies; outside CNS.
What does the autonomic nervous system do?
It is concerned with regulation of smooth muscle, cardiac muscle, and glands. Regulation of “vegetative processes” in the body (largely involuntary)
What are the two parts of the autonomic nervous system?
The sympathetic and the parasympathetic
What does the sympathetic division of the autonomic nervous system do?
Controls functions that accompany arousal and expenditure of energy.
When an organism is aroused (excited or afraid), what does the sympathetic nervous system do?
Increases blood flow to skeletal muscles, stimulates the secretion of epinephrine (which causes increased heart rate and increased blood sugar level), stimulates sweat glands, and causes piloerection (goose bumps).
Where are the cell bodies of sympathetic motor neurons located?
In the gray matter of the thoracic and lumbar regions of the spinal cord.
What is the sympathetic ganglia?
Nodules that contain synapses between preganglionic and postganglionic neurons of the sympathetic nervous system; most outside spinal cord; deliver info about stress & impending danger
What do most preganglionic neurons secrete?
Acetylcholine
What do most postganglionic neurons secrete?
Norepinephrine
What does the parasympathetic division of the autonomic nervous system do?
Controls functions that occur during a relaxed state. Involved with increases in the body’s supply of stored energy.
What are some of the bodily functions that the parasympathetic division is involved in?
Salivation, gastric and intestinal motility (movements), secretion of digestive juices, and increased blood flow to the gastrointestinal system.
What do the neurons in the parasympathetic nervous system secrete?
acetylcholine
Where do the neurons in the parasympathetic nervous system exit the spinal cord?
Cervical and Sacral levels
What is an agonist?
A drug that causes an increase in the amount of production and/or release of neurotransmitters
What is an antagonist?
A drug that causes a reduction in the amount of production and/or release of neurotransmitters
What is the difference between a direct and indirect agonist or antagonist?
Direct - bind to receptor at neurotransmitter binding site (opening or preventing from opening ion channel); called competitive bindingIndirect - bind to receptor at a different site than neurotransmitter binding site (e.g., neuromodulator or hormone binding site), thereby opening or preventing from opening ion channel; called noncompetitive binding
How do direct agonists and direct antagonists function differently, aside from increasing or reducing N.T. release (i.e., how do they do that)?
Direct agonists bind to N.T. site and open channel, whereas direct antagonists bind to N.T. site and don’t open channel, but also prevent other N.T. from binding there and opening channel
What are the functions of transporter molecules/proteins and where do they live?
Storage & reuptake of N.T. (i.e., pumping N.T. into vesicles); live in membrane of synaptic vesicles
What is a precursor and what does it do?
A reduced/incomplete form of neurotransmitter or some other substance (e.g., L-DOPA for dopamine); an increase in a precursor can serve as an agonist
What are 6 ways that drugs can serve as agonists?
Be the precursors themselvesStimulate release of N.T. directly at presynaptic membrane (by binding w/ transporter molecule proteins)Stimulate postsynaptic receptorsBlock autoreceptorsBlock reuptakeInactivate AChE
What are 5 ways drugs can serve as antagonists?
Prevent storage of N.T. in vesicles (by blocking transporter protein)Inhibit release of N.T. at presynaptic membrane (by deactivating protein that causes docked vesicles to fuse with presynaptic membrane)Block postsynaptic receptorsInactivate synthetic enzyme meant to transform precursor to N.T.Stimulate autoreceptors
Which drug/agonist corresponds with each of the following functions? (each function listed corresponds with a different drug/agonist)Be the precursors themselvesStimulate release of N.T. directly at presynaptic membrane Stimulate postsynaptic receptorsBlock autoreceptorsBlock reuptakeInactivate AChE
L-DOPABlack widow spider venomNicotine/muscarineClonodineCocainePhysostigmine
Which drug/antagonist corresponds with each of the following functions? (each function listed corresponds with a different drug/antagonist)Prevent storage of N.T. in vesiclesInhibit release of N.T. at presynaptic membraneBlock postsynaptic receptorsInactivate synthetic enzyme meant to transform precursor to N.T.Stimulate autoreceptors
ReserpineBotulinum toxinCurare/AtropinePCPAApomorphine
Which neurotransmitter does each agonist affect?L-DOPABlack widow spider venomNicotine/muscarineClonodineCocainePhysostigmine
DopamineAChAChNorepinephrineDopamineACh
Which neurotransmitter does each antagonist affect?ReserpineBotulinum toxinCurare/AtropinePCPAApomorphine
MonoaminesAChAChSerotoninDopamine
What is the function of presynaptic autoreceptors and where do they live?
Involved in negative feedback loop that inhibits production and/or release of N.T.; live in membrane of terminal button
What are the 2 ways that N.T.s leave the synaptic cleft?
ReuptakeEnzyme deactivation
How does reuptake work?
N.T. is inactivated by protein that binds to it and returns it to terminal button
How does enzyme deactivation work?
Enzyme (e.g., AChE) breaks down N.T. (e.g., ACh), thereby “destroying it”
What are the two neurotransmitters that accomplish synaptic communication?
GABA and Glutamate
True or False: GABA and glutamate are amino acids that function as neurotransmitters
True
Is GABA excitatory or inhibitory?
Inhibitory
Is Glutamate excitatory or inhibitory?
Excitatory
How do GABA and Glutamate work in tandem?
Glutamate is constantly firing off excitatory signals and GABA goes in and inhibits that junk so we don’t get over stimulated
What are GABA and Glutamate responsible for in the brain?
Most local circuits in the brain involve balance between the excitatory and inhibitory influences of GABA and glutamateThey are responsible for most of the information transmitted from place to place in the brain
What is the role of neuromodulators?
They are there to regulate/modulate the information transmission of the glutamate/GABA circuitsThey activate or inhibit circuits of neurons that are involved in particular brain functions
What is the primary neurotransmitter secreted by efferent neurons in the central nervous system?
Acetylcholine (Ach)
What is acetylcholine’s primary action in the brain?
Facilitation
Where are Ach’s terminal buttons distributed?
Widely throughout the brain
What are the three Ach systems that we are concerned with?
Dorsolateral ponsBasal ForebrainMedial Septum
What does the dorsolateral pons pathways do (Ach)?
Cortical activation; to keep the cortex aroused enough to process information. Elicits most of the characteristics of REM sleep. It begins in the pons and projects to different areas of the brains
What does the basal forebrain pathway do (Ach)?
General activation of the cortex and facilitation of learning, especially perceptual learningIt begins at the forebrain and projects to a wide area of the cortex
What does the medial septum pathway do (Ach)?
Regulates the electrical rhythms of the hippocampus and is important in formation of certain kinds of memories. This pathway is one of the first to deteriorate in Alzheimer’sProjects from the septum to the hippocampus.
What deactivates Ach?
It is deactivated in the post-synaptic receptor by the enzyme AChE acetylcholine-esterase (AChE). When AChE comes into contact with Ach, it separates into an acetate and choline. The choline molecule goes back up in the pre-synaptic button, the acetate just keeps on moving and viola, Ach is gone.
What are the different types of Ach receptors?
NictotinicMuscarinic
Where are nictotinic receptors (ionotropic) found?
In the neuromuscular junctions and some in the CNS
What does ionotropic mean?
It has rapid firing
Where are the muscarinic receptors (metabotropic) found?
In the heart and smooth muscle; predominately in the CNS
What does metabotropic mean?
It has slower firing
What is a neuromuscular junction?
The connection between a motor neuron and muscle (it functions just like a synapse, except on one side it’s a muscle rather than another neuron)
What is myasthenia gravis and what does it effect?
It is an autoimmune disease that affects the nicotinic Ach receptors, that synapse on the muscle. The immune system degrades the neuromuscular junctions. A person with this has a lot of fatigue.
What are some drugs/substances that have effects on Ach synapses?
Botulinum toxin - Ach release is blocked (antagonist - prevents firing)Black widow venom - Ach release is promoted (agonist - increases firing), you convulseAchE inhibitors - inhibits AchE, which means the Ach is not broken down and stays in the synapse longer, and helps slow down the progression of Alzheimer’s
What are the 4 Monoamines (single construction)?
-Catecholamines:1. Dopamine2. Norepinephrine3. Epinephrine (not widely used for brain)-Indolamine:1. Serotonin
Where are the neurons located that produce the monoamine NT’s?
In the small nuclei in the brain stem and axons that branch widely throughout the brain.
Depending on the Post-Syn Receptor, does Dopamine have excitatory or inhibitory influences?
Both excitatory and inhibitory (again, depending on the Post-Syn Receptor)
What areas of functioning does dopamine mainly influence in the brain?
Learning, attention, movement, and reinforcing effects of drugs.
What is the multi-step metabolic process of NT production that comes from catecholamine synthesis?
Tyrosine –> L-dopa –> Dopamine (NT) –> Norepinephrine (NT)Each get converted into the other through the metabolic process
What are the 3 most important systems of Dopamine (very important NT in brain) used in the brain?
- Nigrostriatal = cell bodies that project from the subtantia nigra to the caudate nucleus and putamen in basal ganglia (helps control motor function; Parkinsons).2. Mesolimbic = cell bodies in the tegmental area that project to the limbic system: nucleus accumbens (helps reinforce effects of substance use; and in the amygdala and hippocampus, it helps learning and memory).3. Mesocortical = cell bodies in the ventral tegmental area that project to prefrontal area (helps with judgment, planning, strategy formation, problem-solving, and working memory).
What is one of the main causes for Parkinson’s Dz, and what is it treated with?
Parkinson’s is due to inadequate amounts of Dopamine due to substantia nigra degeneration, does not cross the BBB.Treated with L-dopa (increases amount of Dopamine temporarily).
Is there only one or many types of Dopamine receptors?
Various types of Dopamine receptors (all are metabotropic) that are designated by subtypes (D1 = exclusively Post-Syn; D2 = Pre and Post-Syn).
Are stimulants (cocaine, caffeine, amphetamines, etc.) considered agonists or antagonists?
Stimulants site of action is at dopamine receptors. Stimulant drugs, including: cocaine, amphetamines, Ritalin, caffeine, etc. are agonists, because they block reuptake of dopamine and the drugs spew dopamine and norepinephrine back into the synapse and brain (by diffusion).
What is an example of an antagonistic drug?
Chlorpromazine (generic for Thorazine – first drug used to treat schizophrenia). It blocks D2 receptors.
Explain the use of MAOI’s
-Dopamine is a member of the Monoamine (MAO) group.-In the Pre-Syn Terminal, excess Dopamine is destroyed by MAO.-One of the first drugs used for Depression.-Inhibiting MAO results in increase in Dopamine and Norepinephrine, which increased moods.-However, additional negative side effects.
Norepinephrine is the same as what?
Noradrenergic/noradrenalin
Adrenaline is said to be the same as what?
Epinephrine which is brain but “not very important”
Where is the hormone adrenalin produced?
Adrenal cortex
Cell bodies of neurons that secrete Norepinephrine are located in several nuclei in what three parts of the brain?
Pons, medulla, and one in the thalamus
Which cell body is considered the most important? What does it do?
Locus coeruleus in the pons, involved in vigilance and attentiveness to the environment
The locus coeruleus gives rise to what fiber system?
Norepinephrine fiber system which helps disperse NE to the rest of the brain
Name three places in the brain that NE is spread to and originates from the Locus Coeruleus.
Cerebral cortex, cerebellum, thalamus, olfactory bulb, amygdaloid body, caudal raphe nuclei
What parts of the brain receive input from norepinephrine (NE)?
Almost every region receives input
What type of synaptic effects does Norepinephrine cause?
Excitatory and inhibitory
What are the behavioral effects of NE (norepinephrine)?
Excitatory, increasing vigilance and attentiveness to the environment
There are receptors in the organs of the body that are responsible for the effect of catecholamines when they act as what?
Hormones
What is serotonin also known as?
5HT
Where are 98% of serotonin cells located? How many are in the brain?
98% are located in the gut and 2% of serotonin cells in the brain.
Where are the 2% of serotonin cells located in the brain and where do they project to?
Located in the brainstem raphe nuclei and project to cortex
Name some of serotonin’s behavioral effects
Regulation of mood, control of: eating, sleeping, dreaming and arousal, as well as regulation of pain
What is the precursor for serotonin?
Tryptophan
Where are the cell bodies of neurons that secrete serotonin?
In raphe nuclei in mid brain, pons and medulla
Where does the dorsal raphe project serotonin?
To the cortex and basal ganglia
Serotonin is projected to the cortex, dentate gyrus of hippocampal formation by what?
Median raphe
How many different types of 5- HT receptors are there?
At least 9
Drugs that alter serotonin in its normal process
Prozac, Paxil, Zoloft, Fenfluramine, LSD, MDMA (ecstasy) these are SSRI
Glutamate is the same things as glutamic acid. T or F?
True
How many types of receptor sites does glutamate interact with?
4
One of the receptors sites that glutamate interacts with is NMDA, how many binding sites work together in the NMDA?
6 different binding sites working in concert
What does glutamate help control in the NMDA receptor site?
The Calcium channel CA++
Why is it important that the 6 different binding sites in NMDA in which glutamate interacts with, work in concert?
To produce changes in the synapse important for learning and memory formation
What drug binds at glutamate sites?
PCP
True or false: GABA is the most important inhibitory neurotransmitter in the brain?
True
True or False: GABA has a very limited distribution throughout the brain and spinal cord?
False, GABA appears to have a widespread distribution
What would happen if the brain did not the inhibitory synapses?
The brain would become unstable. Neurons would excite neighbors who would excite their neighbors eventually exciting the original neuron. Eventually most neurons of the brain would be firing uncontrollably. AKA a seizure-epilepsy.
What are the 5 binding sites at the GABA synapses?
GABABenzodiazepine (alcohol also likes to bind here)BarbituratesSteroidPicrotoxin
Are alcohol, benzodiazepine, and barbiturates agonists or antagonists? Also what is there common function?
Agonists (for GABA), they produce relaxation and sedation.
Do we know if the brain produces a ligand that is agonist and naturally produces the same effect as alcohol, benzodiazepine, and barbiturates?
No, we do not know.
True or false: The brain produces an antagonist ligand which causes an increased level of fear, anxiety, and tension?
True, this possibly serves as a protective function in times of danger.
What are Peptides made of?
Two or more amino acids linked together by peptide bonds.
Where are Peptides released from and where do their molecules go when they are released?
All parts of the terminal button, not just from the active zone. Only a portion of the molecules are released into the synaptic cleft, the rest affect other receptors in the area.
True or False: Most peptides appear to serve as neuromodulators, but some act as neurotransmitters.
True
What are endogenous opioids?
A class of peptides secreted by the brain that act as opiates.
What are opiates, such as heroin, morphine, demerol, codeine, and percodan?
Synthetic opioids (neurotransmitter associated with pain reduction)
What is the ligand that is antagonist and blocks the effects of opiates? It is used to treat an overdose of heroin.
Naloxone
What do the various substances derived from lipids do?
Serve to transmit messages within or between cells. (act as neurotransmitters)
What are endocannabinoids?
A lipid; an endogenous ligand for cannabinoid receptors, which also bind with THC, the active ingredient of marijuana.
Why is it considered safe to use THC to treat the nausea associated with chemotherapy in children?
They don’t experience the psychoactive effects of the drug.
What are the six areas of the brain where Cannabinoid (CB) receptors are concentrated in?
Frontal cortex, anterior cingulate, basal ganglia, cerebellum, hypothalamus, hippocampus
What is the level of toxicity for THC and why?
Low level of toxicity because very low level of CB receptors in the brainstem (low chance of overdose and death)
Where are the six terminal buttons CB receptors found?
GlutamateGABAAChNorepinephrineSerotoninDopamine
What is Nitric Oxide (NO)?
A gas produced by cells in the nervous system; used as a means of communication between cells.
True or False: 50 times more animals are killed by the Humane Society than are killed in animal research.
True
Why do Physiological psychologists study animals?
to learn of the relation between physiology and behavior
Animal studies are justified on the basis of..? Name 3 things
1) Minimized pain and discomfort2)The value of the information gained from the research(e.g. Progress in developing vaccines &Progress in preventing cell death immediately after a stroke).3) The importance of science for understanding ourselves and animals
What is Ablation?
involves the destruction of brain tissue followed by an assessment of subsequent changes in behavior
When using ablation in animal research, how do the experimenters control for the stress the animal endures throughout the procedure?
They use sham surgeries as controls (put animal through the entire procedure except for the actual ablation)
Name 5 Ablation techniques.
*Electrolytic lesions/Radio Frequency lesions*Excitotoxic lesions (kainic acid)*Neurochemical lesions (6-OHDA)*Aspiration*Knife cuts
Why are brain lesion studies complicated?
all regions of the brain are interconnected
In terms of Ablation/lesions in animals, what tool is used in stereotaxic surgery and how does it function?
A stereotaxic instrument holds the head in a fixed position.The instrument has an arm that can move in 3 dimensionsThe surgeon can thus position an electrode or other device within a particular sub-cortical structure(think creepy pics from slides)
What is a stereotaxic atlas in terms of stereotaxic surgery?
provides a series of drawings of brain structures Each page is a section of brain relative to a landmark on the skull (such as bregma)
In terms of ablation and lesions in animal research, what are Histological techniques used for?
used to verify the placement of a lesion within brain
What are steps common in histological techniques when creating lesions in animals’ brains?(4 steps)
1) Perfuse (to remove blood from brain)2) Fix brain in formalin to solidify tissue3) Slice brain into thin sections (10-80 microns thick)4) use stains to highlight selective neural elements
Name 3 examples of stains used to highlight selective neural elements.
1) Weil stain (myelin)2) cresyl violet (cell body)3) golgi stain (membrane)
What two types of microscopes used for animal brain research?
electron microscope & confocal laser (can also image living tissue)
In terms of defining neural connections, what are anterograde labels?
They are used to trace efferent connections in the brain.They are taken up by the cell bodies and trasported to axons.
What are retrograde labels?
They are used to trace afferent connections in the brain. They act “backwards” by being taken up in the axons and then transported to the cell bodies.
Name an example of a anterograde label and a retrograde label used in neuro research.
anterograde: lectin PHA-Lretrograde: fluorogold
What can we use to identify lesions in (living) human brains? (name 3)
CT scansMRIMRI DTI
What is a CT scan?
Computerized tomography uses an x-ray beam to scan the brain from all angles, these scans are then summarized in an image of the skull and brain (in a horizontal plane)
Who are CT scans best for?
people with metal plates, skull fractures, and acute brain bleeding.
What is a MRI?
Magnetic Resonance Imaging (MRI) uses a magnetic field and radio waves to excite hydrogen molecules, the resulting information is combined to form an image of tissue
What is a MRI DTI?
Diffusion Tensor Imaging–measures the migration of water molecules along / across axons. Think of a handful of spaghetti. With this, you can trace where the tracks start and where they end up
What can we use to record neural activity in the brain? (3)
microelectrodes (can record the activity of a single or a few neuron(s)), Macroelectrodes (large regions of the brain–EEG), and Megnetoencephalopathy (uses magnetic fields to detect electrical impulses)
What 3 ways can we record metabolic or synaptic activity in the brain?
*measure FOS protein*PET scan (measure glucose consumption in your brain)*fMRI (detect level of oxygen consumption in the brain blood vessels)
What is an FOS protein and how is it measured in neuro research?
Fos protein is produced in nucleus when a neuron is activatedFos protein can be measured just after a behavior of interest has occurred (Neurons with increased Fos levels were active during that behavior)
What is a PET scan a variation of?
The animal 2-DG technique
What is the procedure of a PET scan?
Human subject is injected with radioactive 2-DG, which is taken up by brain cells.As the radioactive molecules decay they emit positrons that can be detected by a scanner
A PET scan indicates the relative activity of …?
different brain regions during mental states
Which scanners have higher temporal and spatial resolution, fMRI or PET?
fMRI
Artificial stimulation of the brain involves what two types of stimulation?
electrical and chemical.
Electrical stimulation of the brain involves…?
passing an electrical current through a wire inserted in the brainCan be used for brain mapping.
Chemical stimulation of the brain can involve…?
infusion of an excitatory amino acid (such as glutamate) into a region
Which type of brain stimulation is more specific, chemical or electrical?
Chemical (e.g. glutamate activates cell bodies, not axons)
How do we use magnets to stimulate the brain for research?
Transcranial Magnetic Stimulation (TMS)
How do we use genetics for neuro research? Name 3 methods
Concordance raes of disorders in mono and dizygotic twins.Adoption StudiesTargeted mutations or knockout genes (defective gene produced in lab and inserted in mice)
