Human Neuro Study Deck Test 1 Flashcards
The brain is made up of approximately how many neurons?
100 Billion
Neurons have a nucleus that contains _____?
Genes
Neurons have specialized projections called _____ and _____.
Dendrites and Axons
The _____ of a neuron bring information TO the cell body.
dendrites
The _____ of a neuron take information AWAY from the cell body.
axons
Through what kind of process do neurons communicate with each other?
Electrochemical
Neurons form specialized connections called “synapses” and produce special chemicals called _____ that are released at the synapse.
neurotransmitters
Approximately how many neurons do we have in the human brain?
1 Quadrillion
Is it true that we only use 10% of our brains?
No
How much does the adult human brain weigh?
Between 1300-1400 g or
Approximately 3 lbs
How long is a neuron?
Anywhere from less than a millimeter to about a meter (3 feet)
Name some of the levels that neuroscientists study.
Behavioral Level
System Level
Local Circuit Level
Single Neuron Level
Synapse Level
Membrane Level
Genetic Level
At what level of neuroscience do we study what causes people and animals to do the things they do?
Behavioral Level
At what level of neuroscience do we study the various parts of the nervous system like the visual or auditory system, which could also include investigations of what parts of the brain are connected to other parts?
System Level
At what level of neuroscience do we study the functions of groups of neurons (nerve cells)?
Local Circuit Level
At what level of neuroscience do we study what individual neurons do in relation to some “event,” or study what is contained within a particular neuron?
Single Neuron Level
At what level of neuroscience do we study what happens in the space between neurons?
Synapse Level
At what level of neuroscience do we study what happens at ion channels?
Membrane Level
At what level of neuroscience do we study the ____ basis of neuronal function?
Genetic Level
What contains the neuron’s nucleus and organelles, and is responsible for maintaining the cell’s health and metabolism?
Cell Body (Soma)
What are the tree-like extensions of a neuron that receive electrical signals from other neurons and convey this information to the cell body?
Dendrites
What is a long, thin fiber that transmits electrical signals away from the cell body to other neurons, muscles, or glands?
Axon
What is a fatty layer that wraps around the axon of some neurons, speeding up the transmission of electrical signals?
Myelin Sheath
What are gaps in the myelin sheath that allow for the rapid transmission of electrical signals along the axon?
Nodes of Ranvier
What are the endpoints of the axon where neurotransmitters are released to communicate with other neurons or muscles?
Axon Terminal (Terminal Buttons)
What are the chemical messengers that neurons use to communicate with each other across synapses?
Neurotransmitters
Based on functions, what type of neurons, also known as afferent neurons, are responsible for converting external stimuli from the environment into internal electrical impulses, transmitting sensory information from the skin, muscles, and sensory organs to the central nervous system?
Sensory Neurons
Based on functions, what type of neurons, also known as efferent neurons, convey impulses from the central nervous system to the muscles and glands, causing them to contract or secrete products, respectively, enabling bodily movements and responses to the environment?
Motor Neurons
Based on functions, what type of neurons are located within the central nervous system and connect sensory and motor neurons and carry out complex processing and integrative functions, are involved in reflexes, neuronal circuits, and the processing of information in the brain?
Interneurons
Based on location, what type of neuron resides within the brain and spinal cord and is responsible for processing and integrating sensory information, generating thoughts and emotions, and initiating motor responses?
Central Nervous System (CNS) Neurons
Based on location, what type of neurons are located outside the central nervous system and include sensory neurons that bring information into the CNS and motor neurons that carry commands from the CNS to muscles and glands in the body?
Peripheral Nervous System (PNS) Neurons
Based on structure, what neurons are characterized by having one axon and multiple dendrites extending from their cell body and are the most common type of neuron in the central nervous system and are typically involved in motor functions and interneuronal communication?
Multipolar Neurons
Based on structure, what neurons have two processes extending fro the cell body: one axon and one dendrite, and are primarily found in sensory organs, such as the retina of the eye and the olfactory system, and are involved in the transmission of sensory information?
Bipolar Neurons
Based on structure, what neurons have a single process that extends from the cell body and divides into two branches far from the cell body: one connected to dendrites that receive sensory information and another that transmits information to the central nervous system? They are primarily found in the peripheral nervous system and are involved in transmitting touch, pain, and temperature sensations.
Unipolar Neurons
Based on structure, what neurons lack a distinct axon and have dendrites that look similar to each other, and are found in the brain and retina where they play roles in interneuronal communication without producing action potentials? They mainly modulate the electrical activity of neighboring neurons.
Anaxonic Neurons
Based on structure, what neuron is this?
Anaxonic Neuron
Based on structure, what neuron is this?
Bipolar Neuron
Based on structure, what neuron is this?
Multipolar Neuron
Based on structure, what neuron is this?
Unipolar Neuron
What are the supporting cells of the central nervous system?
Glial Cells (Neuroglia, or “neural glue”)
What is a glial cell that provides support to neurons of the central nervous system, provides nutrients and other substances, and regulates the chemical composition of the extracellular fluid?
Astrocyte or “star cell”
What is a type of glial cell in the central nervous system that forms myelin sheaths, surrounds axons and insulates them, preventing messages from spreading between adjacent axons?
Oligodendrocyte
What is the smallest type of glial cell that acts as a phagocyte and protects the brain from invading microorganisms?
Microglia
What is a cell in the peripheral nervous system that is wrapped around a myelinated axon, providing one segment of its myelin sheath?
Schwann Cell
What is a semipermeable barrier between the blood and the brain produced by cells in the walls of the brain’s capillaries?
Blood-Brain Barrier
What is the electrical charge across a cell membrane; the difference in electrical potential inside and outside the cell?
Membrane Potential
What is the state of a neuron when it is not being altered by excitatory or inhibitory postsynaptic potentials at approximately -70 mV in the giant squid axon?
Resting Membrane Potential
What is the reduction (toward zero) of the membrane potential of a cell from its normal resting potential?
Depolarization
What is an increase in the membrane potential of a cell, relative to the normal resting potential?
Hyperpolarization
What is the brief electrical impulse that provides the basis for the conduction of information along an axon?
Action Potential
What is the value of the membrane potential that must be reached to produce an action potential?
Threshold of Excitation
In reference to membrane potential, what is the movement of molecules from regions of high concentration to regions of low concentration?
Diffusion
In reference to membrane potential, what is the attractive force between atomic particles charged with opposite signs or the repulsive force between two atomic particles charged with the same sign?
Electrostatic Pressure
What is an aqueous solution of a material that ionizes a soluble acid, base, or salt?
Electrolyte
What is a charged molecule?
Ion
Which ions are positively charged?
Cations
Which ions are negatively charged?
Anions
Knowing the _____ potential can help you predict which way the ion will move.
equilibrium
At rest, the membrane is permeable to _____, _____, and _____.
potassium, chloride, sodium
The Sodium-Potassium Pump uses energy in the form of _____ to move three sodium ions out of the cell and two potassium ions in. This moves the ions against their electrochemical gradients, which is why it requires energy. The pump functions to keep the ionic concentrations at proper levels inside and outside the cell.
ATP, or Adenosine Triphosphate. This is an energy-carrying molecule found in all living things.
What is a specialized protein molecule that permits specific ions to enter or leave the cell?
Ion channel
What is an ion channel that opens or closes according to the value of the membrane potential?
Voltage-dependent Ion Channel
What is the principle that once an action potential is triggered in an axon, it is propagated without decrement to the end of the fiber?
All-or-None Law
What is the principle that variations in the intensity of a stimulus or other information being transmitted in an axon are represented by variations in the rate at which that axon fires?
Rate Law
What is the conduction of action potentials by myelinated axons in which the action potential appears to jump from one node of Ranvier to the next?
Saltatory Conduction
What is the location on a receptor protein to which a ligand binds?
Binding Site
What is a chemical that binds with the binding site of a receptor?
Ligand
What is a small bud on the surface of a dendrite, with which a terminal button of another neuron forms a synapse?
Dendritic Spine
What is the membrane of a terminal button that lies adjacent to the postsynaptic membrane and through which the neurotransmitter is released?
Presynaptic Membrane
What is the cell membrane opposite the terminal button in a synapse, the membrane of the cell that receives the message?
Postsynaptic Membrane
What is the space between the presynaptic membrane and the postsynaptic membrane?
Synaptic Cleft
What is a small, hollow, beadlike structure found in the terminal buttons; that contains molecules of a neurotransmitter?
Synaptic Vesicle
What is a region of the interior of the presynaptic membrane of a synapse to which synaptic vesicles attach and release their neurotransmitter into the synaptic cleft?
Release Zone
When _____ _____ are conducted down an axon (and down all of its branches), something happens inside all of the terminal buttons. Several synaptic vesicles located just inside the presynaptic membrane fuse with the membrane and then break open, spilling their contents into the synaptic cleft.
Action Potentials
What is a receptor molecule in the postsynaptic membrane of a synapse that contains a binding site for a neurotransmitter?
Postsynaptic Receptor
What is an ion channel that opens when a molecule of a neurotransmitter binds with a postsynaptic receptor?
Neurotransmitter-dependent Ion Channel
What is a receptor that contains a binding site for a neurotransmitter and an ion channel that opens when a molecule of the neurotransmitter attaches to the binding site?
Ionotropic Receptor
What is a receptor that contains a binding site for a neurotransmitter; activates an enzyme that begins a series of events that opens an ion channel elsewhere in the membrane of the cell when a molecule of the neurotransmitter attaches to the binding site?
Metabotropic Receptor
What is a protein coupled to a metabotropic receptor; conveys messages to other molecules when a ligand binds with and activates the receptor?
G Protein
What is a chemical produced when a G protein activates an enzyme; carries a signal that results in the opening of the ion channel or causes other events to occur in the cell?
Second Messenger
What is an excitatory depolarization of the postsynaptic membrane of a synapse caused by the liberation of a neurotransmitter by the terminal button?
Excitatory Postsynaptic Potential (EPSP)
What is an inhibitory hyperpolarization of the postsynaptic membrane of a synapse caused by the liberation of a neurotransmitter by the terminal button?
Inhibitory Postsynaptic Potential (IPSP)
What is the reentry of a neurotransmitter just liberated by a terminal button back through its membrane, thus terminating the postsynaptic potential?
Reuptake
What is the destruction of a neurotransmitter by an enzyme after its release—for example, the destruction of acetylcholine by acetylcholinesterase?
Enzymatic Deactivation
What is a neurotransmitter found in the brain, spinal cord, and parts of the peripheral nervous system; responsible for muscular contraction?
Acetylcholine (ACh)
What is the enzyme that destroys acetylcholine soon after is is liberated by the terminal buttons, thus terminating the postsynaptic potential?
Acetylcholinesterase (AChE)
What is the process by which inhibitory and excitatory postsynaptic potentials summate and control the rate of firing of a neuron?
Neural Integration
Whose experiment in 1921 provided the first proof that nerve impulses are transmitted by chemical means and earned him a Nobel Prize? In this experiment two hearts, one with an intact vagus nerve, and one without, were bathed in saline. The vagus nerve of the first heart was stimulated electrically. Then he transferred the saline from heart 1 to heart 2, which slowed without the stimulation. This demonstrated the chemical substance’s effect.
Otto Loewi
What primary neurotransmitter is secreted by the efferent axons of the central nervous system. All muscular movement is accomplished by its release and it is involved in regulating REM sleep, perceptual learning, and memory.
Acetylcholine
What is a cofactor that supplies acetate for the synthesis of acetylcholine?
Acetyl-CoA
What is the enzyme that transfers the acetate ion from acetyl coenzyme A to choline, producing the neurotransmitter acetylcholine?
Choline acetyltransferase (ChAT)
What does the black widow spider produce that triggers the release of acetylcholine?
Venom
What is a class of amines that includes indolamines. In includes Serotonin and Catecholamines which includes dopamine, norepinephrine, and epinephrine? They are produced by several systems of neurons in the brain and modulate the function of widespread regions of the brain increasing or decreasing the activities of particular brain functions. Because the molecular structures of these substances are similar, some drugs affect the activity of all of them to some degree.
Monoamines
Which drug inhibits the reuptake of dopamine; also known as Ritalin; used to treat children with attention deficit disorder?
Methylphenidate (Ritalin)
What is a class of enzymes that destroys the monoamines; dopamine, norepinephrine, and serotonin?
Monoamine Oxidase (MAO)
What is a neurological disease characterized by tremors, rigidity of the limbs, poor balance, and difficulty initiating movements that is caused by degeneration of the nigrostriatal system and treated with L-DOPA?
Parkinson’s Disease
What is a neurotransmitter found in the brain and in the sympathetic division of the autonomic nervous system?
Norepinephrine
What is a hormone secreted by the adrenal medulla and serves as a neurotransmitter in the brain?
Epinephrine
Also called 5-HT or 5-hydroxytryptamine, and also an indolamine neurotransmitter, what plays a role in the regulation of mood, the control of eating, sleep, dreaming, and arousal, as well as the regulation of pain?
Serotonin
Which amino acid is the precursor of serotonin?
Tryptophan
What drug inhibits the reuptake of 5-HT and is used to treat depression, obsessive-compulsive disorder and some anxiety disorders?
Fluoxetine (Prozac)
What drug stimulates 5-HT2A receptors?
LSD
What drug serves as a noredrenergic and serotonergic agnoist and has excitatory and hallucinogenic effects?
MDMA (ecstasy)
Investigators suspect that at least eight _____ _____ may serve as neurotransmitters in the mammalian central nervous system. Three of them are especially important because they are the most common neurotransmitters in the CNS: Glutamate, Gamma-aminobutyric acid (GABA), and Glycine.
Amino Acids
What is the most important excitatory neurotransmitter in the brain?
Glutamate
What is a drug that binds with the PCP binding site of the NMDA receptor and serves as an indirect antagonist of glutamate? It does not prevent glutamate from binding, but it does bind to a site within the ion channel, preventing the function.
PCP Phencyclidine
What amino acid is the most important inhibitory neurotransmitter in the brain and spinal cord?
Gamma-aminobutyric acid (GABA)
What is a category of anxiolytic drugs that are indirect agonists for the GABAA receptor, and are used for their tranquilizing effects? As indirect agonists, they bind to their own specific site on the GABA_A receptor, distinct from the GABA binding site, and induce a conformational change in the receptor that increases its affinity for GABA.
Benzodiazepine
Concerning amino acids and drug categories, what produces an anxiety-reducing effect?
Anxiolytic
Recent studies have discovered that the neurons of the central nervous system release a large variety of _____ which consist of two or more amino acids linked together by _____ bonds.
Peptides, peptide
What is the class of peptide that is secreted by the brain and acts as opiates? They’re drugs that effect opioid receptors and reduce pain.
Endogenous Opioid
What is a drug that blocks opioid receptors; often used to treat heroin overdose?
Naloxone
What is a lipid; an endogenous ligand for receptors that bind with THC, the active ingredient of marijuana?
Endocannabinoid
What is the first cannabinoid to be discovered and probably the most important one?
Anandamide
What is a bitter-tasting alkaloid drug that blocks adenosine receptors?
Caffeine
What dilates blood vessels and increases the supply of cellular nutrients?
Adenosine
What are the building blocks of nucleic acids, which are molecules that carry genetic information in the cells of all living organisms?
Nucleosides
Approximately how many genes in the human genome have been identified?
31,778
What is a single continuous DNA double helix, or DNA molecule?
Chromosome
Somatic cells are any cells in the body that are not _____ or _____ cells.
Sperm or Egg
In humans, each somatic cell normally contains _____ chromosomes arranged in _____ pairs.
46, 23
Of the 46 chromosomes in humans, 44 are _____, the chromosome pairs 1 through 22 that are identical in both males and females and carry the majority of genetic information.
Autosomes
_____ are the reproductive cells–sperm in males and eggs (ova) in females. They are _____, meaning they contain only one set of chromosomes or half the number of chromosomes of somatic cells.
Gametes, haploid
A normal _____ _____ will carry 23 chromosomes. Sperm can carry either an X or a Y chromosome, resulting in 23, X or 23, Y. In contrast, an egg always carries an X chromosome, 23, X.
haploid gamete
The term _____ refers to cells that have a chromosome number that is an exact multiple of the haploid number. In humans, the haploid number is 23, so euploid cells have chromosomes that are multiples of this number.
Euploid
A _____ cell has three sets of chromosomes or 69 chromosomes in total. This is not normal for humans and typically results in developmental abnormalities or miscarriages. The same is true for a _____ cell which has four complete sets of chromosomes, or 92 chromosomes in total.
triploid, tetraploid
An _____ cell does not contain a multiple of the haploid number of chromosomes. This means the cell has an abnormal number of chromosomes, which can be either an extra chromosome or one fewer.
aneuploid
_____: This is when a cell has an extra copy of one chromosome. For example, _____21 means there are three copies of chromosome 21. This is the genetic cause of Down syndrome.
Trisomy
_____: This is when a cell is missing a chromosome. For example, _____ X (also known as Turner syndrome) occurs when there is only one X chromosome in a female instead of two.
Monosomy
What term refers to a deviation from the normal number of chromosomes and includes both euploid and aneuploid conditions?
Numerical Chromosomal Abnormality
What syndrome, also known as Trisomy 13, is caused by an extra copy of chromosome 13 and is associated with severe intellectual disability and physical abnormalities?
Patau Syndrome
What syndrome, also known as Trisomy 18, results from an extra chromosome 18 and causes developmental and growth delays, along with a range of health issues?
Edwards Syndrome
What syndrome is the most well-known trisomy, known as Trisomy 21, and is caused by an extra copy of chromosome 21 and characterized by intellectual disability, distinctive facial features, and an increased risk of certain medical conditions?
Down Syndrome
What is the process in which the DNA molecules of the parental chromosomes break and then reconnect to different partners, resulting in chromosomes with a mix of alleles from the two parents? Recombination increases genetic diversity within a species.
Meiosis
What is the process by which a single cell divides to produce two genetically identical daughter cells, each with the same number of chromosomes as the parent cell? This process is used for growth, repair, and asexual reproduction in multicellular organisms.
Mitosis
What is a specialized type of cell division that reduces the chromosome number by half, producing four haploid cells (gametes) from one diploid cell? This is essential for sexual reproduction, as it ensures that when a sperm and egg combine, the resulting zygote has the correct diploid number of chromosomes.
Meiosis - Reduction Division to Half
What is the process of forming the gametes, sperm in males and eggs in females, through meiosis? These sex cells are haploid, meaning they contain one set of chromosomes, so that after fertilization the resulting zygote is diploid, containing two sets–one from each parent.
Gametogenesis
What term refers to the brain’s ability to change and adapt as a result of experience?
Neuroplasticity
How long does the nervous system continue to develop?
Through adolescence and potentially adulthood.
What are substances or factors that can cause congenital abnormalities or increase the incidence of developmental anomalies in a fetus? They can include a variety of substances that a mother might be exposed to during pregnancy, with critical periods of vulnerability.
Teratogens
What do we call the female gamete?
Ovum
When an ovum and sperm combine they form a what? It is the first cell of a new individual with a complete set of chromosomes.
Zygote
The zygote undergoes cell division and becomes a multicellular organism as it travels down the fallopian tube toward the uterus. Upon reaching the uterus, the zygote implants into the uterine wall and continues to divide. After implantation, the zygote is referred to as an _____.
Embryo
At about 8 weeks, the embryo is typically referred to as a _____. This change reflects significant developmental milestones such as the formation of all essential structures and organs.
Fetus
About how many days after conception does the embryo begin to implant into the uterine wall?
18
In embryonic development, the innermost layer of the embryo’s three primary germ layers will develop into the lining of the digestive tract, liver, pancreas, and other internal organs. What’s it called?
Endoderm
In embryonic development, the middle layer of the embryo’s three primary germ layers will form the muscles, bones, blood vessels, heart, and other structures of the circulatory system, as well as the connective tissue. What’s it called?
Mesoderm
In embryonic development, the outermost layer of the embryo’s three primary germ layers will give rise to the skin, hair, nails, and nervous system. What’s it called?
Ectoderm
What is the specialized area of the ectoderm that forms along the back of the embryo, thickens, and will eventually become the nervous system, including the brain and spinal cord?
Neural Plate
What is the structure created after the formation of the neural plate as it begins to fold inwards? It is the precursor to the central nervous system, and its closure is a critical event. Incomplete closure can lead to serious conditions such as spina bifida.
Neural Groove
What is the first step in the development of the nervous system, during which signals from surrounding tissue cause the ectoderm to thicken and form the neural plate?
Neural Plate Induction
What is the stage in the development of the nervous system in which the cells of the neural plate begin to rapidly divide and multiply, creating the neural tube, which is formed when the edges of the neural plate fold and close, and which then differentiates into the brain and spinal cord?
Neural Proliferation
What step in the development of the nervous system sees the cells migrating to different regions to form the various parts of the CNS, aggregating, and differentiating into specialized neurons and glial cells?
Migration & Aggregation
During what phase of the development of the nervous system do neurons extend axons to reach their target cells and establish connections?
Axon Growth and Synapse Formation
During what phase of the development of the nervous system are neurons and synapses that are not needed or are improperly connected pruned?
Cell Death & Synapse Rearrangement
The development of an organism, particularly during its embryonic and fetal stages, is directed and influenced by _____ signals. These signals can be hormones, growth factors, or other molecular cues that instruct cells to grow, divide, differentiate, or even die (apoptosis).
Chemical
What stage of potency has the potential to create an entire organism because it can give rise to all types of cells in the body? The zygote, which is the cell formed by the union of an egg and sperm, is this.
Totipotent
What stage of potency arises during the stage of development known as the blastocyst, which occurs about 5 days after fertilization? The blastocyst contains an inner cell mass, which is a cluster of cells that can give rise to all the cell types of the body, but not to the extraembryonic tissues. These are the embryonic stem cells. These types of stem cells can be extracted and, under certain laboratory conditions, can be induced to differentiate into virtually any cell type, which holds great potential for regenerative medicine.
Pluripotent
With further development and differentiation, cells lose some of their potency and become _____. This means they can develop into more than one type of cell, but are limited to a specific lineage or tissue type. For example, as the neural tube forms, the cells within it are _____–they can differentiate into various types of nervous system cells, such as neurons, astrocytes, and oligodendrocytes, but they can’t develop into cells outside the nervous system lineage.
Multipotent
What is the innermost layer of the neural tube, lining the central canal? This region contains neural stem cells that are actively dividing during the early stages of brain development and it is adjacent to the ventricles, which are the brain’s internal cavities filled with cerebrospinal fluid.
Ventricular Zone
What do we call the generation of new cells?
Proliferation
The rate of proliferation in the ventricular zone can be _____/min.
250,000
After a daughter cell has been created after mitosis, it typically undergoes a process of differentiation. This means that the cell becomes specialized for a specific function, and, in doing so, becomes “_____” in its role.
Fixed
What is the process during which neurons move from their place of origin to their permanent location? This occurs after the neurons have been generated in the ventricular zone of the neural tube.
Neuronal migration
What are the special glial cells that act as scaffolding for migrating neurons?
Radial Glia
After neurogenesis occurs in the ventricular zone, newly generated neurons migrate through the ____ zone to reach their final destination.
Intermediate
After migrating through the intermediate zone, neurons develop into the cortical layers of the brain in the _____ zone.
Marginal
The _____ plate is the area where the neurons settle to form the layers of the cortex.
Cortical
What word refers to the clustering of neurons once they reach their destination, where they begin to form the structures and circuits necessary for brain function?
Aggregation
What are dynamic, actin-supported extensions of a neuronal axon tip that play a critical role in the navigation of neurons towards their synaptic targets? The _____ _____ actively explores the environment through filopodia (thin extensions) and lamellipodia (sheet-like extensions), responding to various molecular cues.
Growth cone
What are substances that attract growth cones, leading them toward areas with higher concentrations of these molecules? They are critical for guiding axons toward their final target locations.
Chemoattractants
What substances repel growth cones, causing them to grow away from areas with higher concentrations of these molecules? This is important for preventing axons from growing into incorrect pathways.
Chemorepellants
What term refers to a family of proteins that are critical for the survival, development, and function of neurons? They can prevent programmed cell death, stimulate the growth of axons and dendrites, and enhance synaptic plasticity, which is essential for learning and memory.
Neurotrophins
Between _____-_____ of neurons made will die after migration due to failure to compete for chemicals provided by targets.
40-75%
What is another word for cell death?
Apoptosis
What is the process of forming new synapses between neurons?
Synaptogenesis
Neurons develop more _____ branches postnatally, which increases the number of possible connections each neuron can make with other neurons.
dendritic
What is the process by which myelin sheaths form around the axons of neurons, which speeds up electrical transmission between neurons?
Myelination
During early development, the brain tends to create more synapses than it will ultimately use. This overproduction is followed by _____ _____, where excess synapses are eliminated. This is thought to contribute to the high level of “plasticity” in the young brain, meaning its ability to reorganize itself by forming new neural connections.
Synaptic pruning
The _____ of the young brain enables a higher capacity for learning and recovery from injury. For instance, if a part of the brain is damaged, other parts can often take over the lost functions, especially in young individuals.
plasticity
_____ _____ deprivation can lead to a reduction in the number of synapses and dendritic spines in the visual cortex, the consequences of this deprivation can include deficits in depth perception and pattern vision.
Early Visual
An _____ ______ provides a variety of stimuli and opportunities for learning and exploration and can lead to a thicker cortex, greater dendritic development, and neurons in can have more synapses per neuron which can enhance neural connectivity and lead to improved cognitive abilities.
enriched environment
What is the last to fully develop in the brain?
The prefrontal lobe
The _____ _____ is believed to be involved in the maturation of cognitive functions, judgment, and decision-making processes. As individuals age, it undergoes both structural and functional changes that can affect these abilities. For example, in adolescents, it is not yet fully developed, which can influence their decision-making and risk assessment. As we age, changes in it can lead to alterations in cognitive abilities, affecting how older adults process information and make decisions.
Prefrontal Cortex
The prefrontal cortex plays a crucial role in _____ _____, which is the ability to hold and manipulate information over short periods. This is essential for reasoning, comprehension, learning, and memory updating.
working memory
The prefrontal cortex is also involved in planning and executing sequences of actions, often referred to as _____ _____. These include the ability to manage time, pay attention, switch focus, plan and organize, remember details, and avoid saying or doing the wrong thing.
executive functions
For a long time, it was believed that neurogenesis only occurred during embryonic development and ceased afterward. However, research has shown that it continues to occur in certain areas of the adult mammalian brain, specifically in the _____ _____, which is involved in the sense of smell, and the _____, which is critical for memory formation and spatial navigation.
olfactory bulb, hippocampus
When a person repeatedly practices a skill, such as playing a musical instrument, the brain undergoes plastic changes to optimize the control and performance of that skill. This is because specific areas of the _____ _____, which are responsible for movement and coordination, become more finely tuned to the demands of the task. It can increase its area of representation for the parts of the body that are being used more frequently and intensively, which enhances the person’s ability to perform the skill.
motor cortex
For musicians, the _____ cortex processes sensory information from the body, including touch and proprioceptive information from the hands. The area of the _____ cortex representing the hands becomes larger than in individuals who do not play an instrument, indicating a greater degree of neural representation and processing for those specific regions.
somatosensory
The three core symptoms of autism are: reduced ability to _____, reduced capacity for _____ _____, and preoccupation with a single subject or activity.
communicate, social interaction
Autism is described as _____, meaning it varies greatly from person to person.
heterogeneous
A small subset of individuals with autism may have _____ syndrome, where they display remarkable abilities in specific areas such as memory, art, music, or mathematical calculations, despite significant cognitive challenges in other domains.
savant
Approximately _____ in _____ individuals with autism may demonstrate savant abilities, indicating a higher prevalence than in the general population.
1 in 10
There is a genetic component to autism, as indicated by a higher prevalence among siblings at _____% and monozygotic twins at _____%,
5 and 60
_____ _____ _____ _____ is a term that encompasses a range of effects that can occur in an individual whose mother drank alcohol during pregnancy. These effects include physical, mental, behavioral, and/or learning disabilities with possible lifelong implications.
Fetal Alcohol Spectrum Disorders
Over 50% of women who could become pregnant are drinking alcohol. _____% of women drink significantly during pregnancy and 10% drink some amount.
2
A glass of wine, a bottle of beer, and a shot of liquor are equated as containing approximately _____ oz of absolute alcohol.
0.5
Regular consumption of _____-_____ oz/day of alcohol during pregnancy is stated to cause fetal brain damage.
1-2
The impact of _____ on Development:
Infant: Issues with sleep, feeding, developmental milestones, muscle tone, and processing sensory information.
Child: Symptoms may include hyperactivity, poor coordination, and learning delays.
Adolescent/Adult: Challenges with judgment, attention, arithmetic, memory, abstract thinking, and managing frustration or anger.
Alcohol
Alcohol is noted to inhibit all stages of brain development except neuronal _____.
death
_____ _____ is diagnosed before the age of 18, and it often impacts a child’s educational performance and indicates significant challenges in mental capabilities and in skills that are necessary for day-to-day living including communication, self-care, and social skills.
Intellectual Disability
_____ factors in intellectual disability refer to cases where the cause is unknown.
Idiopathic
_____ (Chromosomal) conditions, such as anomalies in chromosome number or structure, are known causes of intellectual disability.
Genetic
People with Down Syndrome often experience _____ physical growth, resulting in shorter stature and sometimes _____ developmental milestones.
delayed
_____ ______ may have certain physical characteristics including:
A flat face with a short nose
Low-set ears
A thickened tongue
Broad hands with a single crease in the palm
Short fingers and toes.
Down Syndrome
What is the neurodevelopmental disorder characterized by a consistent pattern of inattention and/or hyperactive and impulsive behavior that interferes with functioning or development?
Attention-Deficit/Hyperactivity Disorder
What is the electrical potential difference (voltage) across a cell’s plasma membrane?
Membrane potential
At rest, a neuron has a membrane potential called a resting membrane potential, which is typically between _____ and _____ millivolts. The inside of the neuron is negatively charged relative to the outside.
-60 and -70
Resting potential is primarily established by the uneven distribution of ions across the cell membrane. _____ and _____ ions are more concentrated outside the cell, while _____ and negatively charged proteins are more concentrated inside.
Sodium and chloride, potassium
The cell membrane is semi-permeable, allowing some ions to pass through more easily than others. It has protein _____ that are specific for certain ions.
channels
_____ ions tend to diffuse out of the neuron due to a high internal concentration, moving toward a lower concentration outside the neuron. This movement is facilitated by _____ leak channels.
Potassium
The movement of potassium, or _____ out of the cell results in a more positive charge outside and a more negative charge inside, establishing the electrical component of the electrochemical gradient.
K+
To maintain the resting membrane potential, the neuron uses active transport called the _____-_____. This uses adenosine triphosphate (ATP) to move three Na+ sodium ions out of the cell and two potassium ions into the cell against their concentration gradients.
sodium-potassium pump
When a neuron is activated by a stimulus, the _____ of the membrane to ions changes, leading to a deviation from the resting membrane potential. This can result in depolarization, hyperpolarization, or repolarization.
permeability
If the depolarization reaches a certain threshold, typically around -55mV, it triggers an _____ _____. This is a rapid, transient reversal of the membrane potential, where the inside of the cell becomes positive relative to the outside.
action potential
During an action potential, _____-_____ _____ _____ open, allowing sodium ions to rush into the cell due to the electrochemical gradient, causing the inside of the membrane to become positively charged.
voltage-gated Na+ channels
Shortly after the peak of the action potential, voltage-gated Na+ channels close, and _____-_____ _____ _____ open. This allows potassium ions to move out of the cell, restoring the negative charge inside the cell.
voltage-gated K+ channels
The membrane potential may briefly become more negative than the resting potential due to the K+ channels remaining open a bit longer. This is called hyperpolarization. During this time, the neuron is less likely to fire another action potential, known as the _____ period.
refractory
What are the G-protein-coupled receptors that, when bound to their respective neurotransmitter, initiate a signaling cascade involving second messengers within the cell? This process can modulate a variety of cellular processes and often has a longer-lasting effect. For example, this receptor is activated by glutamate and can affect many different cellular processes.
Metabotropic Receptors
These receptors form an ion channel pore, which opens to allow ions like Na+, K+, Ca2+, or Cl- to pass through the membrane in response to the binding of a neurotransmitter. This typically results in a more immediate and short-lived change in the membrane potential of the target cell. Examples include the NMDA, AMPA, and GABA_A receptors.
Ionotropic Receptors
What is an excitatory neurotransmitter with metabotropic receptors and ionotropic receptors such as NMDA and AMPA, which are critical in learning and memory?
Glutamate
What is the main inhibitory neurotransmitter in the brain, with the B version being metabotropic and the A version being ionotropic receptors that usually cause hyperpolarization of the neuron, making it less likely to fire an action potential?
GABA (Gamma-aminobutyric acid)
What is involved in both the central nervous system and the peripheral nervous system, with muscarinic _____ receptors being metabotropic and nicotinic _____ receptors being ionotropic, affecting muscle control and memory?
Acetylcholine (Ach)
What is a neurotransmitter important in reward, motivation, and motor control, with dopamine receptors acting as metabotropic receptors?
Dopamine (DA)
What neurotransmitters are also hormones involved in the body’s fight-or-flight response, with adrenergic receptors being metabotropic?
Norepinephrine (NE) and Epinephrine (Epi)
What is involved in mood regulation, appetite, and sleep, with various serotonin receptors like 5-HT1, 5-HT2, etc., most of which are metabotropic except for 5-HT3, which is ionotropic?
Serotonin (5-HT)
This is the biosynthesis pathway of the catecholamines, which are neurotransmitters that play an important role in the regulation of the nervous system: Fill in the Blanks.
_____: This is an amino acid that serves as the starting point for the synthesis of catecholamines. It can be obtained from dietary sources or produced from phenylalanine in the body.
_____: Tyrosine is converted by the enzyme tyrosine hydroxylase. This is a rate-limiting step, meaning it is one of the slower steps in the synthesis process and thus controls the rate of the production of the final products.
_____: L-DOPA is then converted by the enzyme DOPA decarboxylase (aromatic L-amino acid decarboxylase). Dopamine itself is a neurotransmitter important for reward and motivation, among other functions.
_____: Dopamine is then converted by the enzyme dopamine β-hydroxylase. Norepinephrine is involved in the body’s fight-or-flight response and also acts as a neurotransmitter in the brain.
Tyrosine
L-DOPA
Dopamine
Norepinephrine
The following is the biosynthetic pathway of serotonin, a key neurotransmitter that affects mood, social behavior, appetite, digestion, sleep, memory, and sexual desire and function: FIll in the blanks:
_____: This is an essential amino acid, meaning that it cannot be synthesized by the human body and must be obtained from the diet. Tryptophan is the precursor to serotonin.
_____ (5-HTP): Tryptophan is converted into 5-HTP by the enzyme tryptophan hydroxylase. This is the rate-limiting step in the synthesis of serotonin. Tryptophan hydroxylase can be inhibited by stress or a lack of cofactors such as iron or vitamin B6, which can affect the production of serotonin.
_____ (5-HT, or serotonin): 5-HTP is then converted to serotonin by the enzyme aromatic L-amino acid decarboxylase (also known as 5-HTP decarboxylase). The availability of 5-HTP directly influences the production of serotonin.
Tryptophan
5-hydroxytryptophan
5-hydroxytryptamine
A bundle of axons traveling together is called a what?
Nerve
