CAL

Question 1

What types of receptors are dopamine receptors?

Answer 1

GPCR

Question 2

What do D1 receptors do?

Answer 2

D1 and D5 subtypes

- post-synaptic activate adenylate cyclase

Question 3

What do D2 receptors do?

Answer 3

D2,3,4 subtypes

• inhibit adenylate cyclase
• activate K+ channels
• reduce calcium conductance
• potentiate ATP-mediated arachidonic acid release

Question 4

Which dopamine receptor subtypes are found in the limbic system?

Answer 4

D1, D5, D2, D3

Question 5

Which pathways involved dopamine?

Answer 5

• nigrostriatal
• mesolimbic
• mesocortical
• tuberoinfundibular

Question 6

What is the route of the mesolimbic system?

Answer 6

Ventral tegmental area of midbrain -> axons project to nucleus accumbens and olfactory tubercle
- hyperactivated in schizophrenia

Question 7

What is the route of the mesocortical system? What is its function?

Answer 7

Ventral tegmentum of midbrain -> axons project to frontal and cingulate cortex

• hypoactivated in schizophrenia
• responsible for memory, motivation, emotional, reward, desire, addiction

Question 8

What is the route of the tuberoinfundibular pathway? What is its function?

Answer 8

• links arcuate nucleus of hypothalamus to pituitary

- hormone regulation, maternal behaviour, pregnancy and sensory processes?

Question 9

What pathways involve serotonin?

Answer 9

5-HT neurone cell bodies in raphe nuclei in the pons

• caudal nuclei in lower brainstem projects to medulla
• rostral nuclei in upper brainstem projects to forebrain

Cell bodies also in locus coeruleus

Question 10

What types of receptors does serotonin act on?

Answer 10

GPCR
7 families
Except 5-HT3 which are ligand gated ion channels

Question 11

What do 5-HT1 receptors have in common?

Answer 11

• coupled to adenylate cyclase by G protein

- G protein also directly activates K+ channels reducing neuronal excitability

Question 12

5-HT1a receptors

Answer 12

Inhibitory somatodendritic autoreceptors

Activate K+ conductance via G protein = post synaptic hyperpolarisation

Question 13

5-HT1b receptors

Answer 13

Inhibitory autoreceptors and heteroreceptors

Presynpatic

Question 14

5HT1c receptors

Answer 14

5-HT2c

Question 15

5HT1d receptors

Answer 15

A and B types

B - cranial vessels, sumatriptan vasoconstricts them counteracting CGRP vasodilation in a migraine

Question 16

5HTf receptors

Answer 16

Uterus

Question 17

5-HT2 receptors

Answer 17

Coupled to inositol phosphate

Question 18

5-HT2a receptors

Answer 18

Frontal Cortex, widespread
tracheal/bronchial SM contraction, platelet aggregation, increases capillary permeability
Anxiety, depression, nociception

Question 19

5-HT2b receptors

Answer 19

GIT contraction

Gut, heart, kidney, lung, cortex, limbic

Question 20

5-HT2c receptors

Answer 20

5-HT1c
spinal and supraspinal
Choroid plexus endothelial cells = CSF formation

Question 21

5-HT3 receptors

Answer 21

Ligand gated
Depolarisation, neuronal excitation, inhibition of transmitter release
Emetic - area prostrema
Amygdala - anxiety
Dorsal horn of primary afferents
GI tract

Question 22

5-HT4 receptors

Answer 22

Positively coupled to adenylate cyclase
Reduces K+ and increases Ca2+ conductance = relaxation of oesophageal SM
- indirectly releases Ach contracting GIT SM and increases cardiac force and rate of contraction

Question 23

5-HT6 receptors

Answer 23

Positively coupled to adenylate cyclase

Antidepressants target

Question 24

5-HT7 receptors

Answer 24

Positively coupled to adenylate cyclase

Neuroleptics target