Brainscape's Knowledge GenomeTM

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


See full index

Psychopharmacology > Chapter 4: psychosis and neurotransmitter networks > Flashcards

Chapter 4: psychosis and neurotransmitter networks Flashcards

1
Q

3 subtypes of psychosis

A

paranoid
disorganized/excited
depressive

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

dopamine hypothesis of psychosis

A

caused by hyperactivity of D2 receptors in the mesolimbic pathway

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

how is dopamine synthesized

A

tyrosine is taken up into dopaminergic neurons and converted to DOPA which is then converted to dopamine to be stored in synaptic vesicles

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

what happens to excess dopamine

A

it can be destroyed in neuron by MAOA and MAOB

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

enzymes that convert tyrosine to DOPA and DOPA to dopamine

A

tyrosine hydroxylase
DOPA decarboxylase

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

primary pathway for dopamine termination

A

reuptake into presynaptic neuron via DAT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

secondary inactivation of dopamine

A

extracellularly by COMT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what does COMT stand for

A

catechol-O-methyltransferase

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

how is dopamine terminated in the PFC where DATs are sparse

A

by COMT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how is dopamine inactivated when NO DATs are present

A

diffusion away from synapse to a noradrenergic neuron where it binds to NET and enters the neuron as a false substrate

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

how many groups of postsynaptic dopamine receptors are there

A

2 (D1-like receptors and D2-like receptors)

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

which dopamine receptors are D1-like postsynaptic receptors

A

D1 and D5

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

purposes for D1-like dopamine receptors

A

excitatory
positively linked to adenylate cyclase
stimulates the postsynaptic neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

which dopamine receptors are included in the D2-like group

A

D2, D3, D4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

main functions of D2-like postsynaptic dopamine receptors

A

inhibitory
negatively linked to adenylate cyclase
inhibits postsynaptic neuron

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

what dopamine receptors are also located presynaptically

A

D2, D3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

function of presynaptic D2 and D3 receptors

A

act as autoreceptors to inhibit further dopamine release

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

which presynaptic dopamine receptor is LESS receptive to dopamine

A

D2
takes a higher concentration of dopamine to activate it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

where are presynaptic D2 and D3 receptors located

A

axon terminal
somatodendritic area

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

location of mesocortical dopamine neurons

A

arise from ventral tegmental area (VTA) in the brain stem and project to the PFC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how is dopamine regulated in the VTA

A

by somatodendritic auto receptors D2 and D3 in axon terminals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is different about dopamine autoreceptors in the PFC

A

not many of them to inhibit dopamine release and not many DATs for termination so it is free to diffuse further away from the synapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is true about dopamine’s diffusion radius

A

larger the radius the more concentrated dopamine becomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

location of mesolimbic dopamine neurons

A

project from VTA to striatum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how are mesolimbic dopamine neurons regulated in the VTA

A

somatodendritic D3 auto receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

how are mesolimbic dopamine neurons regulated in the PFC

A

presynaptic D2 auto receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

is dopamine excitatory or inhibitory

A

both. It depends on which receptor subtype it binds to

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

4 classic dopamine pathways

A

-tuberoinfundibular
-thalamic
-nigrostriatal
-mesolimbic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

location of tuberoinfundibular dopamine pathway

A

project from the hypothalamus to the pituitary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

function of dopamine neurons in the tuberoinfundibular dopamine pathway

A

inhibit prolactin release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

location of thalamic dopamine pathway

A

arises from multiple sites
-periaqueductal gray matter
-ventral mesencephalon
-various hypothalamic nuclei
-lateral parabrachial nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

function of thalamic dopamine pathway

A

under investigation
no evidence that malfunctioning is present in schizophrenia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

location of nigrostriatal dopamine pathway

A

projects from dopamine neurons in the brainstem substantia nigra to the striatum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

main function of nigrostriatal dopamine pathway

A

part of the extrapyramidal motor system that controls motor function and movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

receptors, location, and results of direct nigrostriatal dopamine pathway

A

-D1 excitatory receptors
-projects from striatum to globus pallidus interna
-results in stimulation of movement

36
Q

what causes movement disorders

A

too much or too little dopamine in the direct and indirect nigrostriatal dopamine pathway

36
Q

receptors, location, and results of the indirect nigrostriatal dopamine pathway

A

-D2 receptors
-projects from globus pallidus externa and subthalamic nuclei to the globus pallidus interna
-blocks motor movements

37
Q

what types of movement disorders are caused by excessive dopamine in the nigrostriatal pathway

A

chorea
dyskinesias
tics

38
Q

what can happen with chronic blockade of D2 receptors

A

tardive dyskinesia

39
Q

location of mesolimbic dopamine pathway

A

projects from midbrain VTA to the nucleus accumbens in the ventral striatum

40
Q

what is the nucleus accumbens and what does it do

A

part of the limbic system involved in pleasurable sensations, euphoria or drug abuse, and delusions/hallucinations

41
Q

what happens when there is too much or too little dopamine in the mesolimbic dopamine pathway

A

too much - causes positive symptoms of psychosis
too little - anhedonia, apathy, lack of energy, negative symptoms of schizophrenia

42
Q

what is the classic dopamine hypothesis

A

dopamine hyperactivity in the mesolimbic pathway hypothetically accounts for positive symptoms of psychosis in any disorder in which they are present

43
Q

what substances can cause dopamine hyperactivity in the mesolimbic pathway

A

psychostimulants

44
Q

what is thought to cause cognitive, and negative symptoms of schizophrenia

A

hypoactivity of dopamine in the mesocortical pathway projections to the DLPFC

45
Q

what is thought to cause the affective symptoms of schizophrenia

A

dopamine hypoactivity in the mesocortical pathway projections to the VMPFC

46
Q

location of mesocortical dopamine pathway

A

project from cells in the VTA to areas of the PFC

47
Q

glutamate hypothesis of schizophrenia and psychosis

A

NMDA glutamate receptors at critical synapses in the PFC are hypofunctional

48
Q

what are some things that can disrupt NMDA glutamate receptors

A

-neurodevelopmental abnormalities in schizophrenia
-neurodegenerative abnormalities in dementia
-receptor blocking by dissociative anesthetics like ketamine and PCP

49
Q

where is glutamate synthesized when used as a neurotransmitter

A

synthesized from glutamine in glia cells

50
Q

intracellular transporter to return glutamate to glia for storage

A

EAAT

51
Q

how is glutamate synthesized

A

glutamate is converted to glutamine in glia and then released by reverse transporter SNAT. when SNAT reverses back into the cell glutamine catches a ride back in and is then converted back to glutamate and transported into synaptic vesicles via VGluT for release during neurotransmission

52
Q

what is the enzyme that converts glutamate to glutamine

A

glutamine synthetase

53
Q

which enzyme converts glutamine back into glutamate

A

glutaminase

54
Q

how is glutamate terminated

A

when EEATs move it into glia for the cycle to begin again; not via enzymatic breakdown

55
Q

what are the two glutamate cotransmitters

A

amino acids:
glycine
D-serine

56
Q

what is required for glutamate to utilize NMDA receptors

A

a cotransmitter

57
Q

where does glycine come from

A

glycine neurons (little)
glia (most)
synthesized from L-serine
derived directly from dietary amino acids

58
Q

2 ways D-serine cotransmitter is synthesized

A

-L-serine is converted to D-serine by enzyme D-serine racemase in glia
-SHMT converts glycine to L-serine which is then converted to D-serine by racemase

59
Q

name of presynaptic uptake pump for glutamate

A

EAAT - clears excess glutamate out of the synapse

60
Q

name of intracellular vesicular transporter for glutamat

A

vGluT

61
Q

what are glutamate receptors that are linked to G proteins called

A

metabotropic glutamate receptors

62
Q

2 types of glutamate receptors

A

metabotropic
ionotropic

63
Q

what is the NMDA glutamate hypofunction hypothesis

A

psychosis may be caused by dysfunction of glutamate synapses at certain GABA interneurons in the PFC

64
Q

what happens when glutamate neurons that innervate the VTA/mesostriatal dopamine neurons lose their GABA inhibition

A

they become hyperactive and stimulate excessive dopamine release causing positive symptoms of psychosis

65
Q

what happens when glutamate neurons that innervate the VTA/mesocortical dopamine neurons become hyperactive

A

dopamine release is inhibited and can lead to the negative symptoms of psychosis

66
Q

what is the serotonin hypothesis of psychosis

A

psychosis results from hyperactivity/imbalance of serotonin activity (mainly at 5HT2A)

67
Q

how is serotonin synthesized

A

amino acid tryptophan is transported from plasma into brain where it is converted to 5HTP by tryptophan hydroxylase. AAADC then converts 5HTP to 5HT which is then taken up to be stored in synaptic vesicles

68
Q

how is serotonin action terminated

A

-when it is destroyed by MAO enzymes
-when it is taken back up into neuron by SERT

69
Q

which receptor is the axon terminal autoreceptor to shut down serotonin activity

A

5HT1B/D

70
Q

presynaptic serotonin receptors

A

5HT1B/D
5HT1A
5HT2B

71
Q

which receptors are somatodendritic serotonin autoreceptors

A

5HT1A
5HT2B

72
Q

difference between when serotonin binds with 5HT1A and 5HT2B receptors

A

when it binds with 5HT1A it shuts down serotonin impulse flow and when it binds to 5HT2B it increases serotonin impulse flow

73
Q

where are 5HT1A and 5HT2B primarily located

A

midbrain raphe

74
Q

which 5HT1A receptors promote the release of other neurotransmitters

A

ones located primarily on postsynaptic GABA interneurons

75
Q

how do 5HT1A receptors located on GABA neurons promote the release of other neurotransmitters

A

serotonin action at these receptors inhibit the GABA interneurons which increases the release of downstream norepinephrine, dopamine, and acetylcholine

76
Q

is 5HT1B excitatory or inhibitory

A

inhibitory

77
Q

are 5HT2A receptors excitatory or inhibitory

A

excitatory

78
Q

what is a heteroreceptor

A

receptor for a neurotransmitter other than the one the neuron uses as its own (a serotonin receptor on a GABA neuron)

79
Q

are 5HT2A receptors excitatory or inhibitory

A

excitatory

80
Q

how does action at 5HT2A sites affect the release of other neurotransmitters

A

depends on their location. If receptors are located on glutamate neurons excitatory glutamate is released onto downstream targets. When localized on GABA neurons inhibitory GABA release is promoted

81
Q

are 5HT2C receptors excitatory or inhibitory

A

excitatory but since they are mostly located on GABA neurons, they promote GABA release, which inhibits any neuron it innervates downstream

82
Q

where are 5HT3 receptors located

A

on a particular type of GABA interneuron in the PFC

83
Q

are 5HT3 receptors inhibitory or excitatory

A

excitatory on GABA neurons so it has a net inhibitory effect

84
Q

which neurotransmitters specifically does action at 5HT3 receptors on GABA neurons inhibit

A

inhibits release of acetylcholine and norepinephrine

85
Q

are 5HT7 receptors inhibitory or excitatory

A

excitatory on GABA neurons so there is a net inhibitory effect

86
Q

what are the three pathways linked to hallucinations/delusions

A

-dopamine hyperactivity at D2 in mesolimbic/mesostriatal pathway
-NMDA receptor hypoactivity at GABAergic interneurons with a loss of GABAergic inhibition in the PFC
-serotonin hyperactivity/imbalance at 5HT2A receptors on glutamate neurons in the cerebral cortex

Psychopharmacology (13 decks)

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