Dopamine

Question 1

What is dopamine derived from?

Answer 1

Tyrosine amino acid derived from dietary sources

Question 2

Rate limiting step in dopamine regulation

Answer 2

Tyrosine hydroxylase

Question 3

Dopamine synthesis steps

Answer 3

Tyrosine 
| (Tyrosine hydroxylase)
DOPA 
| (DOPA decarboxylase)
Dopamine

Question 4

How is dopamine reuptaken?

Answer 4

Via dopamine transporter

Question 5

Why type of receptors does dopamine exert an effect on?

Answer 5

Dopaminaergic GPCR

Question 6

What are D1 receptors coupled to (signal transduction)?

Answer 6

Gs coupled - activates adenylyl cyclase

Question 7

What are D2 receptors coupled to (signal transduction)?

Answer 7

Gi/Go coupled - inhibits adenylyl cyclase - activates K channels, inhibits Ca channels

Question 8

What does D1 receptor activation result in?

Answer 8

Phosophorylation of voltage gated channels & ionotropic receptors for GABA and glutamate

Question 9

What does D1 receptor activation result in?

Answer 9

It opposes the effects of D1 receptor activation

Question 10

List the major metabolites of dopamine degradation

Answer 10

DOPAC & HVA

Question 11

Dopaminergic neuronal cell location

Answer 11

Substanstia nigra –> projects to the caudate-putamen (Striatum)

Question 12

Importance of dopamine

Answer 12

facilitation of voluntary movement

Question 13

What does damage to dopaminergic pathway result in?

Answer 13

Sensory neglect
Motivational deficits
Motor impairment

Question 14

Dopaminergic pathways

Their importance

Answer 14

Mesocortical & Mesolimbic pathway

Importance in higher level brain function & reward

Question 15

What is the common reward pathway for drug abuse?

Answer 15

Mesolimbic system

Question 16

Some effects of dopamine in the CNS

Answer 16

• Influences growth hormone release (Stimulatory)
• Controls prolactin secretion by the pituitary gland (Inhibitory effects on its release)
• Role in reward