neurotransmitter pathways

Question 1

: How do psychoactive drugs affect neurotransmission?

Answer 1

They interfere with neurotransmitter (NT) systems, either directly (at receptors) or indirectly (by altering NT levels).

Question 2

what is a direct agonist

Answer 2

A drug that mimics a neurotransmitter by binding to the receptor and opening the channel.

Question 3

what is a direct antagonist

Answer 3

A drug that blocks the receptor without activating it, preventing channel opening.

Question 4

what is an indirect agonist

Answer 4

A drug that increases NT availability (e.g., increases production or blocks reuptake), enhancing the chance of receptor activation.

Question 5

what is an indirect antagonist

Answer 5

A drug that reduces NT availability (e.g., disrupts production), decreasing receptor activation.

Question 6

how are neurons organised in the NS

Answer 6

Cell bodies cluster (nucleus & cortex in CNS, ganglia & retina in PNS); axons travel in bundles (tracts in CNS, nerves in PNS).

Question 7

what are the two ways to identify NT pathways

Answer 7

Anatomically (by location and connections) and chemically (by the type of NT used throughout the pathway)

Question 8

what causes schizophrenia in terms of NT activity

Answer 8

Overactivity of dopamine in the mesolimbocortical (MLC) pathway due to excess dopamine or overly sensitive receptors.

Question 9

how is schizophrenia treated and what side effect may occur

Answer 9

Antipsychotic drugs reduce dopamine activity; side effects can include movement disorders.

Question 10

what causes parkisons disease

Answer 10

underactivity in the NS pathway due to lack of dopamine

Question 11

what is a common treatment for parkinsons and its effect

Answer 11

L-DOPA increases dopamine levels; side effects may include psychotic symptoms.

Question 12

what is the key lock principle in neurotransmission

Answer 12

Each neurotransmitter binds only to specific receptor types, and different receptors can have different effects.

Question 13

what happens when dopamine binds to D1 vs D2 receptors

Answer 13

D1 activates second messengers (opens channels); D2 inhibits them (closes channels).

Question 14

why does receptor distribution matter in brain function

Answer 14

Different brain regions have different dopamine receptor subtypes, influencing how drugs and NTs affect them.