7.6 Neuromodulatory Transmitter Systems Flashcards Preview

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Flashcards in 7.6 Neuromodulatory Transmitter Systems Deck (21)
1

What is a neuromodulator?

Substance of transmitters which modulate the efficacy of synaptic transmission but cannot produce firing alone
Mainly act via metabotropic receptors

2

What are the catecholamines?

Dopamine and noradrenaline

3

What is the biosynthesis of catceholamines?

Tyrosine (tyrosine decarboxylase) - L-DOPA (amino acid decarboxylase) - Dopamine (dopamine B hydroxylase) - Noradrenaline (phenylethanolamine-N-methyltransferase) Adrenaline

4

Which molecule in the biosynthesis of catecholamines can cross the BBB?

L-DOPA

5

What breaks down catecholamines?

MAO and COMT

6

Where are the dopamine nuclei found and where do thy project to? and which diseases are implicated in each?

Substantia nigra - project to the striatum of the basal ganglia and facilitate the initiation of movement - PARKINSONS

Ventral tegmental area: innervate the forebrain which includes the pre-frontal cx and parts of the limbic system - SCHIZOPHRENIA

7

Where does the noradrenergic system start and project to?

Starts in the locus coeruleus and the reticular formation and projects to many parts of the cortex including the cerebellum, thalamus, neocortx, hypothalamus, amygdala and hippocampus

8

What is the transduction and function of the NA system?

Transduction is via adrenergic receptors
Function: attention and vigilance and phasic changes in levels of attention

9

What drug acts on the NA system?

Amphetamines

10

What are the ionotropic and metabotropic receptors for serotonin?

Metabo: 5-HT 1,2 and 4-7
Iono: 5-HT3

11

What does serotonin need to be made?

Vitamin B6

12

Where are serotonin neurons located and where do they project to

Locates in the raphe nucleus (caudate and rostral) with very dense and profuse innervation

13

What is the function of the serotonin system?

Sleep-wake cycle
Aggression and impulsivity
Anxiety and depression
Descending pain control

14

What drugs exert their effects through the 5-HT system?

LSD

15

What is the iono and metabotropic receptors for ACh?

Iono: pentamer of 2a, Ib, Igamma, 1 delta subunis
Metabo: M1-5

16

Where are ACh neurons found and where do they project to?

Basal forebrain: nucleus basils and septal nuclei
- hippocampus and all neocortex
Pontomesencephalo-tegmental complex
- thalamus and part of forebrain

17

What is the function of the cholinergic system?

Learning and memory - alzheimers
Arousal and sleep/wake cycle

18

What drug acts on the cholinergic pathway?

Muscarine

19

What is the receptor for orexin/hypocretin?

Metabotropic - OXIR1 and 2 which is coupled via Gq to IP3 pathway

20

How is orexin/hypocretin broken down?

internalised as receptor/transmitter

21

What is the function of the hypocretin/orexin system?

Master system
Provides wakefulness
At the interface between CNS and ANS - plays a role in metabolism and BP