Behavioral Neuroscience: Exam 1 Flashcards
1
Q
Cartesian Dualism
A
The idea that the universe consists of two elements: physical matter and the human mind (soul, self or spirit). The mind and brain are viewed as separate entities.
2
Q
Watson
A
A behaviorist who believed that all behavior was the product of learning (nurture).
3
Q
Ethology
A
The study of animal behavior in the wold, focuses on intrinsic (nature) behaviors.
4
Q
Evidence of Evolution
A
- Fossil evidence of evolution.
- Structural similarities among living species, suggesting common ancestors.
- Impact of selective breeding.
- Direct observation of evolution in progress (finches of the Galapagos Islands changed dramatically after one season of drought).
5
Q
Evolution of Vertebrates
A
- Chordates have dorsal nerve cords***
- Vertebrates are chordates with spinal bones
6
Q
Evolution of Amphibians
A
- Bony fishes leave the water briefly
- Advantages include fresh water and new food sources
7
Q
Evolution of Reptiles
A
- Lay shell covered eggs, covered by dry scales
- Can live far from from water
8
Q
Evolution of Mammals
A
- Develop mammary glands to nurture young
- Eventually no longer lay eggs, raise young in mother’s body
- Humans emerge from the order primates
9
Q
Emergence of Humankind
A
- Humans belong to family Hominids, genus Homo
- First homo species emerged from Australopithecus 2 million years ago
- Homo sapiens emerged 200,000 years ago
10
Q
Homologous Structures
A
Similar structures due to a common evolutionary origin.
11
Q
Analogous Structures
A
Similar structures without a common origin (Ex: Birds and Bees, both developed wings from separate origins).
12
Q
Convergent Evolution
A
The evolution of similar solutions to the same environmental demands by unrelated species.
13
Q
Evolution of the Human Brain
A
- There is no relationship between brain size and intelligence
- Brain size is generally correlated with body size
- More informative to look at relative size of different brain regions
- The human brain has increased in size during evolution
- Most of the increase in size has occurred in the cerebrum
14
Q
Gene
A
Genetic material, composed of DNA (Deoxyribonucleic acid).
15
Q
Chromosome
A
Slender thread inside a cell’s nucleus that carries genes.
16
Q
Genotype
A
Our genetic makeup.
17
Q
Phenotype
A
Our observable traits.
18
Q
Dominant Gene
A
Gene that masks other genes’ effects. When it is present it dominates.
19
Q
Recessive Gene
A
Gene that is expressed only in the absence of a dominant gene.
20
Q
Dichotomous Traits
A
A phenotypic (observable) trait that exists in one form, or another, but never in combination (Ex: eye color).
21
Q
True-Breeding Lines
A
Interbred members always produce offspring with the same trait.
22
Q
Mendel’s Experiment - Essay Question
A
Mendel had a true-breeding line of brown peas and a true-breeding line of white peas in his garden. He decided to plant one of his white pea plant seeds in the brown planter. When he returned he found that all of the offspring where brown. Once the brown offspring reproduce he found that 25% of the offspring have white seeds. Created the logical explanation for recessive and dominant genes.
Why does the first generation have no white seeds? Why does the second generation have white seeds?
23
Q
Homozygous
A
2 identical alleles (BB, ww)
24
Q
Heterozygous
A
2 different alleles (Bw)
25
Chromosomes
- Genes are located on chromosomes in the nucleus of each cell
- Humans have 23 pairs of chromosomes, with an allele on each chromosome
26
Meiosis
A process of cell division that yields cells with just 23 chromosomes (splitting). This is how you get separate egg and sperm cells - only cells in your body that only have 23 chromosomes, not 46.
27
Gametes
Egg cells and sperm cells.
28
Zygote
Fertilized egg cell that has 23 pairs of chromosomes.
29
Mitosis
A form of cell division that yields daughter cells that have 23 pairs of chromosomes (copying).
30
Epigenetics - Short Answer
Your genes and your environment are always interacting, your environment is constantly changing the expression of your genes. All of your phenotypic traits are the result of your genes being influenced by your environment.
31
Nucleotide-Bases - Short Answer
The four building blocks of life:
1. Adenine - only connects to Thymine
2. Thymine
3. Guanine - only connects to cytosine
4. Cytosine
32
DNA Replication
As the two strands of the original DNA molecule unwind, the necleotide-bases on each strand attach free-floating complementary bases. Once the unwinding is complete, two DNA molecules, each identical to the first, will have been created.
33
Sex Chromosomes
The 23rd pair of chromosomes. The first 22 pairs are called autosomal.
```
Female = XX
Male = XY
```
34
Sex-Linked Traits
Influenced by genes on the sex chromosome. Dominant traits on the X chromosome will be seen more commonly in females, recessive ones in males.
35
Gene Expression - *Essay Question*
1. Strand of DNA unravels around the specific gene.
2. mRNA leaves nucleus and attaches to ribosome in the cell's cytoplasm.
3. Ribosome synthesizes protein according to 3-base sequences (codons) of mRNA (translation).
36
Regulation of Gene Expression
1. Enhancers: Stretches of DNA that determine whether particular structural genes initiate the synthesis of proteins and at what rate.
2. Transcription factors: Proteins that bind to DNA and influence the extent to which genes are expressed.
3. Epigenetics: The pattern of actual gene expressions, vs. the genes possessed is most important.
37
Mitochondrial DNA
Mitochondria have their own DNA. Mitochondria are the energy-generating structures found in the cytoplasm of all cells. Mitochondrial DNA may be responsible for some disorders.
- Mitochondrial DNA never splits.
- The only way it changes is through mutation (only mutates through exposure to radiation).
38
Minnesota Twin Study
A study of twins reared apart showed that identical twins are more similar to each other than fraternal twins on all psychological dimensions. Identical twins have a higher correlation of IQ scores.
39
Multiplier Effect
Genetically similar individuals seek out similar environments.
40
Nervous System
A communication network consisting of nerve cells, both inside and outside of the brain and spinal chord. Consists of the central and peripheral nervous system.
41
Central Nervous System (CNS)
Consists of the brain and the spinal chord. Bony protective Armour.
42
Peripheral Nervous System (PNS)
Refers to all of the nerves that are located outside of the brain and the spinal chord. The PNS serves to bring information into the CNS and carry signals out of the CNS.
43
Somatic Nervous System
A subdivision of the peripheral nervous system. Controls the body and voluntary responses.
44
Autonomic Nervous System
A subdivision of the peripheral system. Controls involuntary and automatic responses.
45
Afferent Nerves
Brings information IN to the CNS.
46
Efferent Nerves
Brings information OUT of the CNS.
47
Sympathetic Nervous System
Part of the PNS and a subdivision of the autonomic nervous system. Causes you to startle, heart pace, sweat, fires rapidly in response to threats in the environment.
"Fight or Flight"
48
Parasympathetic Nervous System
Part of the PNS and a subdivision of the autonomic nervous system. Allows you to feel comfort.
"Rest and Relax"
49
Meninges
Layers of tissue between the brain and the skull - three layers.
50
Pia Mater
The first layer of the meninges located closest to the brain - this is the softest layer. Adheres to the CNS surface.
51
Arachnoid Membrane
The second and middle layer of the three meninges. This is a web-like layer that contains cerebrospinal fluid (CSF) and blood vessels.
52
Dura Mater
The third layer of the meninges located closest to the skull. This is the hardest layer - tough outer membrane.
53
Cerebrospinal Fluid (CSF)
Fluid that serves as a cushion. Also located inside the brain and circulates through all of the ventricles - useful for transporting sodium throughout the brain. CSF is made by the choroid plexus.
54
Blood-Brain Barrier
Tightly packed cells of blood vessel walls that prevent entry of many molecules and pathogens to the brain. However, oxygen, carbon dioxide and fats can pass through the barrier freely.
55
What is the chemical protection and the physical protection of the brain? - *test question*
The chemical protection of the brain is the blood brain barrier, and the three physical protections of the brain are the skull, meninges and cerebrospinal fluid (CSF).
56
Neuron
Specialized cells that receive and transmit electrochemical signals - come in many shapes and sizes.
57
Cell Body
The metabolic center of the neuron - filled with cytoplasm.
58
Dendrites
The short processes emanating from the cell body, which receive the synaptic contacts from other neurons.
59
Axon
The long, narrow process that projects from the cell body - it carries an electrochemical message through the neuron.
60
Myelin
The fatty insulation around many neurons.
61
Nodes of Ranvier
The gaps between sections of myelin. They allow the actions potential of the axon to regenerate. In these nodes sodium enters the node and potassium exits.
62
Axon Terminal
The end of the axon which makes a connection with another neuron.
63
Terminal Button
The end of the axon terminal that releases chemicals into synapses.
64
Synapse
The gaps between adjacent neurons across which chemical signals are transmitted - aka the release of neurotransmitters.
65
Two Types of Neural Signals
1. Action Potential (located inside the axon)
| 2. Neurotransmitters (from one neuron to another)
66
Cell Body
Also called the soma. Houses the nucleus which contains DNA. Neurotransmitters and made in the soma.
67
Mitochondria
The sites of aerobic (oxygen-consuming) energy release in the cell.
68
Endoplasmic Reticulum (ER)
Plays a role in the synthesis of proteins (part of the ER with ribosomes) and the synthesis of fats (part of ER without ribosomes).
69
Golgi Complex
A connected system of membranes that packages molecules in vesicles.
70
Microtubles
Responsible for the rapid transport of material through the neuron. These run through the axon of the neuron.
71
Cell Membrane
A lipid bilayer with signal proteins and channel proteins embedded in it to only allow particular molecules and material into the membrane.
72
Glial Cells
- Support cells for the neuron
- Glial cells outnumber nerons 10:1
- Four classes of glial cells
73
Oligodendrocytes
Cells that form the myelin in the CENTRAL nervous system. Web-like (octopus) cells that attach themselves to many others and extensions rich in myelin create myelin sheaths in the CNS.
74
Schwann Cells
Cells that form the myelin in the PERIPHERAL nervous system. These differ from oligodendrocytes, in that these cells completely wrap themselves around one axon at a time, not many.
75
Astrocytes
The largest of the glial cells, and star shaped.
"Handy Man Cell"
They are cells that provide structural support to other cells.
76
Microglia
Tiny cells that clean waste from the nervous system such as dead cells and infections - involved in response to injury or disease.
"EMT Cells"
77
Nuclei - Short Answer
Clusters of cell bodies in the CNS.
78
Ganglia - Short Answer
Clusters of cell bodies in the PNS.
79
Tracts - Short Answer
Bundles of axons in the CNS.
80
Nerves - Short Answer
Bundles of axons in the PNS.
81
Anterograde Tracing
(Forward) Start at the cell body and see where the axon goes.
82
Retrograde Tracing
(Backward) Start at the axon end and follow it back to the cell body.
83
Medial
Toward the middle.
84
Lateral
Toward the side.
85
Proximal
Close
86
Distal
Far
87
4 Major Divisions of the Brain - *Draw These*
1. Spinal Cord
2. Hindbrain
3. Midbrain
4. Forebrain
88
Hindbrain
Includes the medulla (myelencephalon), and the reticular formation, cerebellum and pons (metencephalon).
89
Midbrain
(Mesencephalon) Includes the superior colliculous and inferior colliculous which are visible. Also includes the pariaqueductal gray (PAG), the red nucleus, and the substantia nigra which are not visible.
90
Forebrain
Includes the thalamus and the hypothalamus (diencephalon). Includes the cerebral cortex which is made up of the hippocampus, amygdala, caudate nucleus, putamen, global pallidus, fornix, cingulate, septum, mammillary bodies and the striatum (telencephalon).
91
Cerebellum
Responsible for coordination, balance and timing.
92
Medulla
Controls Breathing and heart rate.
93
Longitudinal Fissure
A groove that separates the right and left hemispheres of the brain.
94
Corpus Callosum
Largest hemisphere-connecting tract.
95
Lateral Fissure
A groove on both sides of the brain that separate the superior part of the brain from the inferior part of the brain.
96
Cerebral Cortex
Outermost part of the forebrain, responsible for analyzing sensory processing and higher brain functions. Controls reasoning, thinking and planning.
97
*4 Lobes of the Brain (Telencephalon)* - Short Answer
1. Frontal Lobe
2. Parietal Lobe
3. Temporal Lobe
4. Occipital Lobe
98
*What are the 5 major subdivisions of the brain?*
```
Telencephalon
Diencephalon
Mesencephalon
Metencephalon
Myelencephalon
```
99
*What are the major fissures of the Telencephalon?*
Central Fissure
Longitudinal Fissure
Lateral Fissure
100
*Cerebral Commissure*
A band of fibers that crosses from left to right. The biggest commissure is the corpus callosum.
101
Resting Membrane Potential
- Inside of the neuron is negative with respect to the outside
- Resting membrane potential is about -70mV
- Membrane is polarized (carries a charge)
102
Factors Contributing to Even Distribution
1. Random motion - particles tend to move down their concentration gradient
2. Electrostatic pressure - like repels life, opposite ions attract
103
Factors Contributing to Uneven Distribution
1. Selective permeability to certain ions
| 2. Sodium-potassium pumps
104
4 Ions Contributing to Resting Potential - Short Answer
1. Sodium (Na+)
2. Chloride (Cl-)
3. Potassium (K+)
4. Negatively charged proteins (A-) Synthesized within the neuron, found primarily within the neuron
105
The Neuron at Rest
- Ions move in and out through ion-specific channels
- K+ and Cl- pass readily
- Little movement of Na+
106
Sodium-Potassium Pump
Active force that exchanges 3 Na+ inside the neuron for 2 K+ outside the neuron.
107
Depolarization
Making the membrane potential less negative. This will cause an excitatory postsynaptic potential (EPSP).
108
Hyperpolarization
Making the membrane potential more negative. This will cause an inhibitory postsynaptic potential (IPSP).
109
What two effects can a neurotransmitter have on a neuron?
1. Depolarization - make it less negative
| 2. Hyperpolarization - make it more negative
110
EPSPs and IPSPs
- Decremental: They get smaller as they travel
- One EPSP typically will not suffice to cause a neuron to "fire", summation (many) are needed
- For an action potential to "fire" the threshold must be reached near the axon hillock
111
Spatial Summation
Integration of events happening at different places - same time but different places
112
Temporal Summation
Integration of events happening at different times - same place, but different times
113
Conduction of Action Potentials
All-or-None
| - When threshold is reached neuron "fires" and the action potential either occurs or it does not
114
Rising Phase
-70mV to +50mV
| Sodium channels open, potassium channels open, sodium channels then close at +50mV
115
Repolarization
+50mv to -70mV
| Sodium channels close at +50mv and potassium channels start to close once potential begins to reach -70mV again
116
Hyperpolarization
-80mV to -70mV
| Potassium channels start to close at -70mV then a drop to -80mV before stabilizing at -70mV
117
Sodium and Potassium Channels - *Essay Question* Action Potentials
The opening and closing of voltage-activated sodium and potassium channels during the three phases of the action potential: rising phase, repolarization and hyperpolarization - *SLIDE 15*
At rest the neuron is at -70mV, chloride is at equilibrium, sodium channels are closed, potassium channels are open and the sodium-potassium pump is always running. EPSP's then come in, neurotransmitters land on the dendrites and depolarize the cell. Once temporal or spatial summation happen to depolarize the neuron to -65mV, all the sodium channels will open. Once all of the sodium rushes in the ce3ll goes from -70mV to +50mV. At +50mV the sodium channels close again. Now, potassium is rushing out of the cell and because it is positively charged this causes the cell to repolarize to -70mV. Potassium continues to leave slowly at -70mV causing the cell to hyperpolarize to -80mV. During hyperpolarization the cell is filled with sodium ions and the cell, so the sodium-potassium pump works to pump sodium out and potassium in to get the cell back to it's resting potential at -70mV.
118
Maximum Velocity of an Axon
60 meters per second.
119
Absolute Refractory Period
Impossible to initiate another action potential.
120
Relative Refractory Period
Harder to initiate another action potential.
121
Small Neurotransmitter Molecules
Synthesized in the terminal button and packaged in synaptic vesicles.
122
Large Neurotransmitter Molecules
Assembled in the cell body, packed in vesicles and then transported to the axon terminal.
123
Exocytosis
The process of neurotransmitter release.
124
Neurotransmitter Release
The arrival of an action potential at the terminal opens voltage activated calcium channels. The entry of calcium causes vesicles to fuse with the terminal membrane and release their contents.
125
Receptors
- Receptors are specific for a given neurotransmitter
| - There are multiple receptor types for a given neurotransmitter
126
Ionotropic Receptors
Associated with ligand-activated ion channels
-Neurotransmitter binds and an associated ion channel opens or closed, causing a PSP.
127
Metabotropic Receptors
Associated with signal proteins and G proteins.
-Effects are slower, longer-lasting, more diffuse and more varied.
128
Reuptake
Recycling of the neurotransmitter.
129
Enzymatic Degradation
A neurotransmitter is broken down by enzymes.
130
Glial Function and Synaptic Transmission
Astrocytes appear to communicate and to modulate neuronal activity. Some connection is through gap junctions between cells.
131
Serotonin
A neurotransmitter involved in mood and temperature regulation, aggression and sleep cycles.
132
Dopamine
A neurotransmitter responsible for motor function and our reward response system - pleasure centers in the brain. Shows up in addiction behavior.
133
Acetylcholine
A neurotransmitter involved with muscle contraction in the (PNS) and cortical arousal in the (CNS). Was the first neurotransmitter to be identified because it was found in the peripheral nervous system.
134
Anandamide
A neurotransmitter involved with pain reduction, and increase in appetite. The receptor was found before the neurotransmitter was found because researchers traced THC molecules.
135
Norepinephrine
A neurotransmitter involved with brain arousal and other functions like mood, hunger and sleep.
136
GABA
The main inhibitory neurotransmitter in the CNS. GABA is synthesized from glutamate.
137
Glutamate
The main excitatory neurotransmitter found in the CNS - participates in the relay of sensory information and learning.
138
Unconventional Neurotransmitters
1. Soluble Gases
| 2. Endacannabiniods
139
Neuropeptides
Large Molecules
| Ex: Endorphins - produce analgesia (pain suppression)
140
7 Steps in Neurotransmitter Action
1. Neurotransmitter molecules are synthesized by enzymes
2. Neurotransmitters are stored in vesicles
3. Neurotransmitters that leak out of the vesicle are destroyed by enzymes
4. Action potential cause vesicles to fuse with the presynaptic membrane and release their neurotransmitter into the synapse
5. Released neurotransmitter binds with autoreceptors and inhibit subsequent neurotransmitter release
6. Released neurotransmitter bind to postsynaptic receptors
7. Released neurotransmitter molecules are deactivated either by reuptake or enzymatic degradation
141
How do drugs influence synaptic activity?
1. Agonists (mimics)
| 2. Antagonists (block)
142
Agonists - Short Answer
Increase or facilitate activity.
143
Antagonists - Short Answer
Decrease or inhibit activity.
