Lectures 1 & 2: Neuroanatomical Structures and Functions

Question 1

Neuroscience: Measure of Internal and External Conditions

Answer 1

Neuroscience always discusses two conditions:

1. Internal – somatic measures
2. External – behavioral measures

Somatic Intervention
Enhancing or decreasing neural function to affect/measure behavior
–e.g. Lesions, Transcranial Magnetic Stimulation

Behavioral Intervention
Measurement of neural activity associated with behaviors
–e.g. fMRI, EEG, ERP

Question 2

3 Levels of Analysis

Answer 2

1. Behavior
2. Brain as a whole – decide if we want to know where or when/how
   FMRI & PET: spatial location
   EEG: timing/amplitude
3. Connections between neurons: DTI diffuser tensor imaging – how water moves through the brain (looking for pathways)

Question 3

Peripheral Nervous System

Answer 3

Sympathetic
o fight or flight
o in addition to activation, it turns off of systems (directing energy toward action e.g. decreased digestion)

Parasympathetic
o rest and digest
• returning to a calm state

Question 4

Miscellaneous class notes

Answer 4

meningitis – the meninges swell, squeeze the brain

cerebrospinal fluid – cleans out debris, acts as a shock absorber – “the cleaner”

traumatic brain injury (TBI) – athletes: most common is football, followed by cheerleading

endorphins primarily aim at allowing the body to repair itself

Nitrous oxide – makes you not care – the pain is still there (it’s been recently reintroduced for pain relief during childbirth)

Question 5

Types of brain cells

Answer 5

Neurons & Glial Cells

Neurons – communicators

Glial cells – support system: Astrocytes, Oligodendrocytes, Schwann Cells

Astrocytes
• energy messengers
• spread from capillaries to neurons carrying oxygenated blood
• serve as a barrier between blood and neurons

Oligodendrocytes
• “insulation”
• create myelination

Schwann cells
• insulation of the larger motor nerves

Question 6

4 Lobes of the Brain

Answer 6

Occipital – primarily vision

Temporal – memory, audition, visual recognition of objects (after being processed in the occipital lobe)

Parietal – spatial reasoning, identification of location of limbs, location of objects visually

Frontal – executive control center

Question 7

Limbic System

Answer 7

Limbic System: “previous experience center”

amygdala

hippocampus – packaging memory

cingulate gyrus – reward and feedback
o helps to modify memories – – not just packaging memory, but providing feedback for adjustment
*highly influential in linking behavioral outcomes to motivation (e.g. a certain action induced a positive emotional response, which results in learning).

hypothalamus – regulatory, hormone release

Question 8

Basal Ganglia

Answer 8

Basal Ganglia: “movement center” – plan and execute movement

• putamen
• caudate nucleus
• globus palladus

Question 9

Thalamus

Answer 9

Thalamus: relay station between sensory systems (except olfactory) and the rest of the cortex

Question 10

Neuron: Electrical and Chemical Gradients

Answer 10

Electrical gradient, resting potential -70 mV

Chemical gradient – lower concentration of sodium ions NA+

Voltage Gated Channels – axon hillock – waiting for a charge
o both Na and Cl are coming in and creating an imbalance

Ligand Gated Channels
o opens with particular chemical key, usually NT

Excitatory Response
• influx of positive Sodium ions, depolarizes neuron, raises potential closer to zero

Inhibitory Response
• influx of negative Cl ions, hyperpolarizes the neuron
Certain neurotransmitters are associated with each
response

Question 11

Action Potential

Answer 11

Action Potential is all or none, a spike

Myelin
o aids conduction, “turns the street into a highway”
o prevents loss of ions
o maintains integrity of action potential

Terminals open, influx of Ca causes the vesicle to merge with cell membrane, opens to release NT’s, Ca channels open

NT’s also attach to autoreceptor to signal their release, to regulate how much NT gets released into synaptic cleft

Every neuron has a baseline firing rate – if it were 0, it would only be able to be excited. By having a baseline, now both directions are possible

Raster: | | | ||| || | | | ||| | |
Each line is a spike
action potential is always the same amplitude
*frequency is the means of communication

Question 12

Otto Kline

Answer 12

frog heart experiment, discovery or the chemical basis of communication

Previously, neurons were thought of as a web, all connected

Question 13

Neurotransmitter Cleanup

Answer 13

1. Degradation – enzymes break down NT
   * monoamine oxidase
2. Reuptake – NT taken back into presynaptic neuron or astrocyte

**There is more than one neurotransmitter in a neuron, but very rarely are there more than one in the same terminal. Different neurotransmitters occupy different terminals

Question 14

Ways to Affect Neurotransmitters

Answer 14

SSRIs

MAOIs

Antagonists – block receptor (e.g. curare – paralysis,
blocks acetylcholine)

Agonist – acts like a neurotransmitter, e.g. nicotine

Slow or speed synthesis of vesicles, e.g. L-dopa

Regulate how much of NT is released – drugs that affect Ca reaction

Question 15

Therapeutic Index

Answer 15

Difference between ED50–LD50

Farther Apart = Safer Drug

Question 16

ED-50

Answer 16

Effective Dose 50

Dose at which drug causes half of its maximal effect

Response without overload

Question 17

LD-50

Answer 17

Lethal Dose 50

Dose at which drug is lethal to half of patients

Question 18

Secondary Binding

Answer 18

System gets flooded with too much of a drug, goes to preferred location but also attaches to other receptors, which causes side effects

Question 19

Efficacy of psychotropic medications

Answer 19

Drugs affect the entire system

MAOI’s affect all of the monoamines, not just serotonin

SSRI’s only affect serotonin

Sometimes the effect is neurobiological based, sometimes only behavioral
“mechanism unclear”
side effects are now termed “unanticipated events”