Lecture4

Question 1

Electrical Synapses

Answer 1

throughout nervous system (retina, thalamus, hypothalamus), not as numerous as chemical, gap junctions, bidirectional flow of info, intracellular channels, very fast and efficient

Question 2

Chemical Synapses

Answer 2

more numerous, unidirectional, facilitatory/excitatory synapses (move target closer to threshold-depolarizing), or inhibitory synapses (move threhold to target cell down-hyperpolarizing)

Question 3

Types of Facilitatory Synapses

Answer 3

axodendritic, axosomatic, axoaxonal (most powerful)

Question 4

Types of Inhibitory Synapses

Answer 4

axodendritic, axosomatic, axoaxonal (most powerful)

Question 5

Neuropharmacology

Answer 5

block or enhance certain channels in gap junctions

Question 6

Nerve Terminal - Chemical Synapses

Answer 6

synaptic vescicles (package of neurotransmitters), mitochondria, lateral zone, active zone, synaptic cleft, receptors

Question 7

Lateral Zone

Answer 7

AP reaching this area allows Ca++ in

Question 8

Active Zone

Answer 8

where the neurotransmitter is released

Question 9

Synaptic Cleft

Answer 9

space between cells, slows the transmission down

Question 10

Receptors

Answer 10

open channels and move closer to or further away from threshold based on ions

Question 11

How could you disrupt the dopamine pathway?

Answer 11

lack of tyrosine, block tyrosine from converting to dopa, block dopamine from packaging into vescicles, block calcium from coming in, block ATP, block postsynaptic receptors, block enzymes

Question 12

Structure of Postsynaptic Receptors

Answer 12

integral proteins-span the membrane, may be many proteins that make up one receptor, affinity for a neurotransmitter, conformational change after binding occurs allowing membrane potential change with ions entering or leaving

Question 13

Function of Postsynaptic Receptors

Answer 13

voltage-gated, ion specific, cotransport systems

Question 14

Post-Synaptic Na+ Channel

Answer 14

MI-MIV domains, 6 different proteins in each domain controlling the gate

Question 15

Post-Synaptic Responses

Answer 15

muscular responses (end plate potential), excitatory CNS responses (EPSP), inhibitory CNS responses (IPSP), modulatory responses

Question 16

Muscular Responses (EPP)

Answer 16

end plate potential, synapse between axon and muscle cell, acetylcholine as transmitter, non-specific ion receptor (any ion can enter)

Question 17

Modulatory Responses

Answer 17

long-term potentiation, learning and memory, post tetanic potentiation

Question 18

Acetylcholine (Ach)

Answer 18

nicotinic or muscarinic

Question 19

Biogenic Amines

Answer 19

molecules that have very similar structure, same precursor and can be converted to others in same class, norepi (+), dopamine (+/-), serotonin (+/-), histamine (+/-)

Question 20

Amino Acid

Answer 20

building blocks of proteins, can be excitatory/inhibitory (GABA - , Gly - , Glut + , Asp + )

Question 21

y-Aminobutyric Acid (GABA) (-)

Answer 21

potent inhibitory transmitter

Question 22

Glutamate (Glut) (+)

Answer 22

potent excitatory transmitter, may have link to cells dying after stroke (“excited to death”)

Question 23

Aspartate (Asp) (+)

Answer 23

resistant to breakdown and may build up inside neurons (don’t drink liquid aspartame aka soda_if still not convinced ask Mike about his “weekly cleaning” on Thursdays)

Question 24

Neuroactive Peptides

Answer 24

about 150, cell signalers, many can act as hormones, have an general or specific effect on neurons

Question 25

Hypothalamic Releasing Hormones

Answer 25

created in hypothalamus (diencephalon) and released into pituitary or general circulation (growth, male/female differentiation)

Question 26

Neurohypophyseal Hormones

Answer 26

direct effects on brain

Question 27

Substance P

Answer 27

transmitter for pain for first order sensory neurons

Question 28

Rate-Limiting Step

Answer 28

Ca++ influx into cell

Question 29

Modulation of Contractile Strength

Answer 29

how much neurotransmitter is sent out based on how much calcium, if more neurons fire–>more neurotransmitter–>more calcium–>more AP–>facilitated response (presynaptic facilitation)

Question 30

Generator Potential

Answer 30

anything that causes change in the resting membrane potential (can be positive or negative), caused by external stimulus, can cause action potential

Question 31

Muscle Tone

Answer 31

leakage of Ach causes low level, constant muscle contraction

Question 32

Presynaptic Inhibition

Answer 32

inhibitory cell can fire and dump inhibiting neurotransmitters on the cell that is attempting to fire and cause contraction

Question 33

Monosynaptic Reflex Arc

Answer 33

sensory receptor–>dorsal root ganglion cell–>alpha motor neuron–>muscle, basis for all spinal level reflexes and selected cranial level reflexes, resultant motor activity is involuntary

Question 34

Interneuron Gating

Answer 34

basis for modulation of our muscle tone, inhibitory interneurons in the motor reflex arc are there to inhibit the motor neuron cell, prevent muscle from over activating, from higher and lower levels

Question 35

Reciprocal Inhibtion

Answer 35

spinal cord “gating” mechanism to prevent co-contraction of agonist/antagonist pairs during volitional or reflex activity

Question 36

Feed-Forward Inhibition

Answer 36

at cortical and spinal cord level, sends signal to muscle and also sends forward inihibitory to antagonist (PNF)

Question 37

Feed-Back Inhibition

Answer 37

collateral branches feedback to inhibitory cells, helps with modulation

Question 38

Divergent Neuronal Circuit

Answer 38

spread info from one cell to large number of cells, sensory systems (benefit is that if some cells get damaged, will still maintain some feeling)

Question 39

Convergent Neuronal Circuit

Answer 39

many cells converging onto one cell, motor systems (benefit is if some cells are damaged, will still have movement but won’t be normal)