lecture 3 continued

Question 1

GABA is synthesized from ________ by _______

Answer 1

glutamate; glutamic acid decarboxylase

Question 2

GABA-A receptors are ________

Answer 2

ionotropic (ligand-gated)

Question 3

benzodiazepines bind to

Answer 3

gamma subunits

Question 4

benzodiazepines enhance the ability of ________ to open receptors to chloride channels

Answer 4

GABA

Question 5

ECl = ___mV

Answer 5

-65

Question 6

GABA receptors oppose _______

Answer 6

action potentials/depolarization

Question 7

Anxiolytic drugs that act on GABA receptors/chloride channels? Anticonvulsive? Insomnia?

Answer 7

diazepam (valium), alprozolam (xanax); diazepam; triazolam (halcion), zolpidem (ambien), flunitrazepam (rohypnol - date rape drug)

Question 8

pentobarbital (barbituate)

Answer 8

anesthetic

Question 9

phenobarbital (barbituate)

Answer 9

anticonvulsant

Question 10

low pregesterone lead to

Answer 10

catemenial seizures

Question 11

glutamate receptors try to depol or hyperpol

Answer 11

depolarize.. GABA hyperpolarizes

Question 12

benzodiazepines ___________ the frequency. of channel-opening events

Answer 12

increase… so they MIMIC GABA

Question 13

barbiturates increase the ______ of GABA-gated chloride channel openings

Answer 13

duration

Question 14

barbituat-induced comas are used to

Answer 14

decrease intracranial pressure via reduced metabolic rate and cerebral blood flow - used after TBI, shock, edema

Question 15

cross tolerance is due to

Answer 15

upregulation of an enzyme in the liver that also breaks down the other drug or substance metabolized

Question 16

short term effects of benzodiazepine (low doses)

Answer 16

euphoria, fatigue, shallow breathing, trouble coordinating movements

Question 17

short term effects of benzos (high doses)

Answer 17

paranoia, aggression, easily agitated, difficulty remembering

Question 18

effects in overdose (benzos)

Answer 18

unconsciousness, respiratory depression, collapse of heart, walking difficulty, CNS depression, rarely. death unless combined w alcohol or opioids

Question 19

long term effects of benzos

Answer 19

tolerance, dependence, withdrawal, increased anxiety, insomnia, CNS excitability

Question 20

barbituates are more or less dangerous than benzos

Answer 20

more

Question 21

GABA A are receptors also known as

Answer 21

gamma amino butyric acid type A

Question 22

benzos increase the _____ but not the ______ of an agonist at GABA A receptors

Answer 22

potency; efficacy

Question 23

ionotropic receptors consist of

Answer 23

Kainate R,s NMDARs (calcium permeable, voltage dependent), AMPARs (calcium impermeable, voltage independent)

Question 24

AMPA and Kainate. receptors mediate the flow of

Answer 24

Na+ - EPSPs

Question 25

NMDA receptors mediate

Answer 25

Na+ and Ca++ - works as a second messenger

Question 26

NMDA receptors are involved in _______ and ______ memory

Answer 26

declarative (hippocampus) and procedural (striatum, motor areas, amygdala, cerebellum)

Question 27

blocking NMDA impairs

Answer 27

learning and memory because they are involved in synaptic plasticity and LTP

Question 28

LTP

Answer 28

long term potentiation - the long lasting strengthing of the connection btwn two neurons

Question 29

NMDA receptors require two diff neurotransmitters to open the channel:

Answer 29

1) glutamate 2) glycine or D-serine (has its own binding site, co-agonist)

Question 30

When the cell membrane is at resting potential, magnesium does what

Answer 30

binds to its location within the NMDA channel to block ions from flowing in (so cell needs to be depol for magnesium to gtfo and let ions flow if glutamate and coagonist are present)

Question 31

drugs that block NMDA

Answer 31

ketamine and PCP

Question 32

PCP is similar to what ion in terms of blocking the channel

Answer 32

magnesium, ketamine does this too

Question 33

explain the mechanism of the “coincidence detector” btwn AMPA and NMDA receptors

Answer 33

glutamate releases and activates both receptors, only AMPA opens, depolarizes membrane, magnesium kicked out, NMDA receptors can now conduct ions like calcium and sodium

Question 34

Hippocampal circuit and LTP

Answer 34

if you stimulate CA3 region which synapses with cells in CA1, strengthen synaptic connections

Question 35

LTP involves insertion of ____ receptors

Answer 35

AMPA

Question 36

NMDA receptors and excitotoxicity hypothesis

Answer 36

the damage produced by exposure to glutamate is caused by a prolonged depol of receptive neurons, causing a large percentage of cell death in a few hours via apoptosis and necrosis

Question 37

in an ischemic stroke where you can’t make enough ATP to maintain potentials and depolarization, ___________ is released and opens ______ channels

Answer 37

glutamate; NMDA – too much calcium is not good for cells

Question 38

necrosis vs apoptosis

Answer 38

necrosis - when many cells die in a few hours (cells burst/lysis due to swelling)

apoptosis - programmed cell death (no lysis, phagocytosed and very clean)

Question 39

mitochondria are like

Answer 39

the buffer of calcium, which is why mitochondrial dysfunction can occur if there’s too much calcium –> necrosis

Question 40

reperfusion of tissue after ischemia causes necrosis because

Answer 40

the mitochondria reuptake a bunch of enzymes and reactive oxygen species that burst and go crazy when they finally receive oxygen