Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Block 3 Up To Quiz 1 > Glutamate and GABA Amino Acid Neurotransmitters, Receptors, and Drugs PT 1 > Flashcards

Glutamate and GABA Amino Acid Neurotransmitters, Receptors, and Drugs PT 1 Flashcards

Up to Pg.8 F Benzodiazepines

1
Q

All CNS neurons carry receptors for

A

inhibitory and excitatory amino acid neurotransmitters

  • aprox 1/3 brain and SC neurons release glutamate
  • aprox 1/3 brain and SC neurons release GABA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Two main amino acid neurotransmitters maintaining balance between excitation and inhibition in normal brain function

A
  • glutamate

- GABA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Important inhibitory amino acid neurotransmitters in vertebrate CNS

A
  • GABA

- Glycine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

GABA mechanism of action

A
  • Opens Cl- permeable GABAa and GABA c channels
  • activates metabotropic receptors that couple to G proteins these GABAb receptors serve inhibitory fxs at pre- and post- synaptic sites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

GABA stands for

A

Gamma-amino butyric acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

drugs that target GABA receptors

A
  • increase CNS inhibition mainly through allosteric mechanisms
  • decrease anxiety (anxiolytic drugs)
  • produce sedation
  • anesthesia
  • some used as anti-convulsants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Mechanisms of drug action GABA receptor targeting drugs

A
  • direct agonists
  • allosteric agonists
  • allosteric antagonists
  • non-competitive
  • uncompetitive types inhibition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

main excitatory amino acid neurotransmitter CNS

A

L-glutamate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

L-glutamate effect on what receptors

A

activates excitatory receptors channels:

  • AMPA-
  • kainate-
  • NMDA-type receptors
  • Metabotropic glutamate receptors couple to G-proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Metabotropic glutamate receptors and G-proteins

A
  • Metabotropic glutamate receptors coupled to G-proteins

- can have inhibitory and excitatory fxs depending on which G-protein its coupled to

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Inhibition of of excitatory receptors in CNS

A
  • decreases activity in CNS pathways that contain them

- Particularly true of NMDA type glutamate receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

NMDA receptors clinically

A

of interest b/c found pain pathways and their inhibition -> amnesia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

GABA fxs where

A
  • principle inhibitory neurotransmitter or brain interneurons
  • main inhibitory amino acid neurotransmitter in dorsal half spinal cord (DH)
  • GABA-containing projection neurons (Purkinje neurons of cerebellum)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

types GABA receptors

A
  • GABAa receptor
  • GABAb receptor
  • GABAc receptor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

GABAa and GABAc receptors

A

anion permeable ion channels complexes of 5 protein subunits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

GABAb receptor

A
  • coupled to G-proteins
  • indirectly coupled via G-protein signaling pathway to voltage-dependent Ca2+ channels (presynaptic) and K+ channels (post synaptic)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

which receptors most important numerically and most diverse and why

A

GABAa b/c composed of 6alpha, 4 beta, and 3 gama subunits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

GABAa receptor activation

A
  1. GABA released
  2. GABAa receptor activated
  3. GABAa receptor opens intrinsic channel
  4. Flux Cl- ions across plasma membrane increases
    5a. If cell resting potential less negative than Ecl cell hyperpolarized
    5b. If cell resting potential more negative than Ecl cell will depolarize
    6b. cell membrane potential negative to action potential threshold
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is affect of GABAa receptor activation and why

A

Ecl more negative than threshold action activation so effect GABAa receptor activation is to keep cell membrane potential negative to action potential threshold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Br- clinical significane

A

GABAa and glycine channels permeable to anions their high Br- permiablity has been exploited to treat canine epilepsy

21
Q

effect of Br- entry through Cl- channels

A

Br- through Cl- channels hyper polarizes neurons and makes them less excitable

22
Q

GABAa receptor fx enhanced by lg # drug types including

A
  • anti-convulsants (anti-epileptics)
  • anti-anxiety drugs (anxiolytics)
  • barbiturates (sedatives, anticonvulsants, anesthetics)
  • injectable anesthetic agents (etomidate, propofol)
  • inhalation anesthetics (isoflurane, halothane ect.)
23
Q

GABAb receptors pre or postsynaptic

A

theyre both

24
Q

activation postsynaptic GABAb receptors causes

A
  • increase in K+ permeablity -> hyperpolarization
25
Q

GABAergic terminals (release GABA) and GABAb receptor

A

receptor activation -> decrease Ca2+ permeability -> decreases NT release

26
Q

GABAb receptor fxly important where

A

in SC and other pts of brain

27
Q

GABAc receptors mainly found where

A

retina

28
Q

GABAc receptors structure

A

-closely resemble GABAa receptors but distinshuised from GABAa group bc contain rho (p) subunits

29
Q

GABAc receptor pharmacology

A
  • has distinct pharmacology bc rho subunit

- ivermectin kills parasites by inhibiting their muscle activity

30
Q

GABA metabolism facts

A
  • pt of pentose shut pathway

- synthesis metabolically favored bc ATP generated

31
Q

GABA metabolism synthesis

A

L-glutamate-> GABA

catalyzed by glutamate decarboxylase (GAD)

32
Q

GABA metabolism breakdown

A

GABA -> succinic semialdehyde catalyzed by GABA transaminase (GABA-T)

33
Q

GABA breakdown and synthesis requires

A

pyridoxal (Vit B6) as a cofactor

34
Q

Synaptic activity termination GABA

A
  • terminated by reuptake through specialized transporters
  • high affinity reuptake mainly into neuronal presynaptic terminal
  • glial cells have lower affinity transporters
35
Q

GABAa receptor agonists endogenous

A

GABA

36
Q

GABAb receptors agonists endogenous

A

GABA

37
Q

GABAc receptors agonists endogenous

A

GABA

38
Q

GABAc receptors agonists synthetic

A

ivermectin

39
Q

GABAa receptor antagonists cause

A

seizures

40
Q

GABAa receptor allosteric modulators mechanism of action

A
  • multiple discrete allosteric sites on GABA receptor-channel complex allosteric modulators enhance GABAa responses
41
Q

Examples GABAa receptor allosteric modulators

A
  • Alcohol
  • Benzodiazepines
  • Barbituates
  • Steroid hormones
  • Inhalation anestetics
  • Newer injectable anesthetics
42
Q

Alcohol GABAa allosteric modulator

A 
Ethanol low dose ->
- decreased anxiety
- elevates mood
- promotes sociability
Ethanol higher doses
- decreases brain activity
43
Q

Benzodiazepines GABAa allosteric modluator

A

minor tranquilizers treat anxiety and pre-anestehtics

ex. Diazepam

44
Q

Barbiturates GABAa allosteric modulators

A
  • important as tranquilizers, pre-anestetic sedatives, short acting injectables used for induction
  • pentobarbital = used for euthanizing in high doses
45
Q

Steroid hormones GABAa allosteric modulators

A
  • endogenous metabolites of progesterone and deoxycortisone potentiate GABAa mediated inhibition in manner similar to barbiturates
46
Q

Inhalation anesthetics GABAa allosteric modulators

A
  • interact in sterospecific manner with specific sites on GABAa subunits and potentiate GABAa- mediated inhibition at concentrations that = anesthetic doses in animals
47
Q

Newer injectable anesthetics GABAa allosteric modulators

A
  • etomidate and propofol

- interact with GABAa receptors at allosteric sites and potentiate GABAa mediated inhibition in CNS

48
Q

phenobarbital does what acts where

A
  • anti-seizure drug

- acts at allosteric site called barbiturate site

49
Q

Injectable anesthetics example and act where

A
  • act at allosteric barbiturate site
  • act directly at neurotransmitter receptor site as direct agonist
    ex. Thiobarbital

Block 3 Up To Quiz 1 (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions