Intro to CNS Pharmacology

Question 1

leak channels open during resting membrane potential

Answer 1

K+, Cl-

Question 2

action potentials: sequence of events

Answer 2

• localized depolarization–>voltage-gated sodium channels open
• voltage-gated potassium channels also open but their opening is more gradual and their inactivation is slower

Question 3

action potentials are ______ and ______ in amplitude

Answer 3

all-or-none, 100 mV

Question 4

synaptic potentials (IPSP, EPSP) are ______ and ______ in amplitude

Answer 4

graded, few mV

Question 5

ways two kinds of EPSPs can occur

Answer 5

• increased conductance EPSPs: open ligand-gated channels for sodium or calcium
• decreased conductance EPSPs: close potassium leak channel

Question 6

way in which IPSP can occur

Answer 6

open ligand-gated channels for potassium or chloride

Question 7

gating mechanism for action potential vs. synaptic potentials

Answer 7

APs: voltage
synaptic: ligand/chemical

Question 8

norepinephrine is important for what and via what receptors?

Answer 8

arousal/wakefulness (alpha receptors), autonomic nervous system regulation (beta receptors)

Question 9

rate-limiting step of norepinephrine synthesis

Answer 9

conversion of tyrosine to L-DOPA by tyrosine hydroxylase

Question 10

co-factor for tyrosine hydroxylase

Answer 10

BH4 (tetrahydrobiopterine)

Question 11

autoreceptor responsible for feed-forward regulation of norepinephrine release (increases release)

Answer 11

beta receptor

Question 12

autoreceptor responsible for feedback regulation of norepinephrine release (decreases release)

Answer 12

alpha2 receptor

Question 13

3 mechanisms of norepinephrine inactivation

Answer 13

1. diffusion
2. reuptake by presynaptic neuron
3. enzymatic inactivation (MAO and COMT)

Question 14

compare the vesicles that hold norepinephrine vs. neurotensin

Answer 14

• norepinephrine: small

- neurotensin: large, dense core

Question 15

norepinephrine vs. neurotensin: compare where they are packaged

Answer 15

• norepinephrine: filled at the terminal

- neurotensin: packaged at the Golgi

Question 16

norepinephrine vs. neurotensin: compare inactivation and what this implies

Answer 16

no reuptake by transporters for neurotensin, which means peptides tend to last longer

Question 17

what are the 3 unique aspects of peptide signaling compared to amine neurotransmitter signaling

Answer 17

less directed, can last longer, lower fidelity