Neurotransmitters 2 - Bizon

Front 1

What kinds of neurotransmitters are the targets of most psychoactive drugs?

Back 1

Biogenic amines (they are implicated in a wide range of complex behaviors)

Front 2

Name the 4 biogenic amines. Which is not a catecholamine?

Back 2

-Dopamine
-Epinephrine
-Norepinephine
-Serotonin (not a catecholamine)

Front 3

Biogenic amines are synthesized by (a few/many) neurons.

Back 3

a few - but have projections to many areas of the brain

Front 4

Biogenic amine neurotransmitters primarily signal by what mechanism?

Back 4

G-protein coupled receptors

(have more of a modulatory role, not fast)

Front 5

Dopamine is initially taken into the cell as ______________ and is converted to ______________ by tyrosine hydroxylase.

Back 5

tyrosine; L-Dopa

Front 6

L-Dopa is converted to dopamine by what enzyme?

Back 6

Dopa decarboxylase

Front 7

Dopamine reuptake into the cell is completed by ____________, and degradation in the cell is completed by _____________.

Back 7

DAT - Dopamine transporter
MAO - monoamine oxidase

Front 8

Along with MAO, what other enzyme degrades dopamine in the synapse?

Back 8

COMT - catechol-O-methyltransferase

Front 9

Name the dopamine receptors found postsynaptically. Which is also found presynaptically?

Back 9

D1-D5; D2

Front 10

T/F Dopamine can have differing effects depending on what receptors it acts on.

Back 10

True

Front 11

What are the two broad classes that these receptors fall into? What are their respective effects?

Back 11

D1-like (D1 and D5) - increase CAMP (activating)
D2-like (D2-D4) - decrease CAMP (inhibitory)

Front 12

Dopamine synthesizing neurons are in what two areas of the midbrain? What are the functions of these two areas?

Back 12

substantia nigra - has projections to substantia and fxns in voluntary movement
ventral tegmental area - projections to nucleus accumbens and limbic system, fxns in reward, reinforcement, cognition

Front 13

Disease associated with the loss of >85% of dopaminergic neurons in the substantia nigra

Back 13

Parkinson's disease

(sxs: muscle rigidity, difficulty initiating movement; slow movement)

Front 14

A common first-line treatment for Parkinson's is _____________. Why is dopamine itself not used?

Back 14

L-dopa; DA doesn't cross the BBB

(also dopamine receptor agonists and MAO inhibitors)

Front 15

Describe how over time a neutral stimulus can trigger DA release.

Back 15

-get release of DA from neurons with pleasurable stimuli - eventually even neutral stimuli paired with pleasurable stimuli start to cause DA release

Front 16

What area of the brain is highly implicated in addiction?

Back 16

Nucleus accumbens

Front 17

Name 2 bits of evidence for the relationship between schizophrenia and dopamine.

Back 17

-drugs that induce dopamine release cause schizophrenia-like symptoms
-antipsychotics with greatest affinity for the D2 receptor require the lowest dosages to help positive sxs of schizo

Front 18

Positive symptoms of schizophrenia are thought to be due to overactivity in the _____________ system; negative symptoms are thought to be due to underactivity in the ______________ system.

Back 18

-mesolimbic overactivity (i.e. too much dopamine, hence antipsychotics help with this)
-mesocortical underactivity (i.e. too little dopamine here, antipsychotics don't help with this)

Front 19

Dopamine is the immediate precursor to what biogenic amine?

Back 19

Norepinephrine

-converted by dopamine beta-hydroxylase

Front 20

Similar to DA, norepinephrine is reuptaken by the cell via a transporter known as _______, and degraded by ________ or ________.

Back 20

-NET - norepinephrine transporter
-MAO - monoamine oxidase or COMT - catechol-O-methyltransferase

Front 21

Norepinephrine is the immediate precursor to what other catecholamine?

Back 21

epinephrine

Front 22

Norepinephrine and epinephrine act on what two classes of receptors? Which are stimulatory and which are inhibitory?

Back 22

alpha and beta adrenergic receptors

-alpha - inhibitory - CAMP down
-beta - stimulatory - CAMP up

Front 23

What receptor serves as the autoreceptor (i.e. it is also found on the presynaptic terminal)?

Back 23

alpha 2

Front 24

NE synthesizing neurons are located in the __________ _________; NE is implicated in what functions?

Back 24

Nucleus coeruleus

arousal, mood, cognition

Front 25

Blocking ___________ receptors has been shown to block emotionally charged memory formation. This could be helpful for what condition?

Back 25

-beta 2 (i.e. give propranolol)

-PTSD

Front 26

Serotonin is derived from what amino acid?

Back 26

Tryptophan

5-Hydrotryptamine = 5-HT = Serotonin

Front 27

What transporter is responsible for the reuptake of serotonin for its degradation? What enzyme degrades it?

Back 27

-SERT - serotonin transporter
-MAO (not COMT because not a catecholamine)

Front 28

Which is the only ligand-gated serotonin receptor? Which is the autoreceptor?

Back 28

-5-HT3

-5-HT1

Front 29

Serotonin producing neurons are located where?

Back 29

Brainstem (raphe nuclei)

Front 30

What kinds of behaviors are implicated with serotonin signaling?

Back 30

-mood, anxiety, eating (also a wide variety)

Front 31

What condition has been associated with a deficit of one or more monoamine systems?

Back 31

Depression

Front 32

What downstream product of monamine synthesis has been proposed to be involved?

Back 32

Brain derived neurotrophic factor (BDNF)