PSYCHOBIOLOGY: neurotransmitter pathways

Question 1

what is the general pathway in the brain?

Answer 1

activity follows specific pathways that are symmetrically arranged on both sides of the midline

Question 2

describe the theoretical implications of brain pathways using Sz & Parkinson’s

Answer 2

sz symptoms = hallucinations & delusions, treated with antipsychotics which can cause motor symptoms

parkinson symptoms = trembling, slowness, treated with l dopa which can cause psychotic episodes

Question 3

describe the classification of neurotransmitters based on chemical structure

Answer 3

• amines
• amino acids
• peptide transmitters
• gas transmitters which are synthesised as needed
• they are chemically related because they are complex versions of one another

Question 4

describe the classification of neurotransmitters based on function

Answer 4

classified based on input / output (glutamate & ACh are excitatory and GABA is inhibitory) and information modulation

Question 5

function of ACh

Answer 5

• activates cerebral cortex
• facilitates learning
• activates muscle fibres for muscle contraction

Question 6

function of dopamine

Answer 6

• voluntary movement
• action planning
• control

Question 7

function of noradrenaline

Answer 7

• increased vigilance & ready to act

Question 8

function of serotonin

Answer 8

• calming
• reduces impulsive behaviour

Question 9

why do NTs have to be constantly synthesised?

Answer 9

they are complex molecules which cannot be stored in large amounts

Question 10

what is a drug?

Answer 10

a substance which affects the brain when it crosses the blood brain barrier via astroglia, having major effects on bodily functions even in small amounts

Question 11

endogenous

Answer 11

substances produced by the body

Question 12

exogenous

Answer 12

substances which enter the bloodstream from external sources

Question 13

what is a psychoactive drug?

Answer 13

a drug that affects the CNS & alters alertness, perceptual, cognitive & / or emotional processes
- all interfere with neurotransmitter systems

Question 14

what are the 4 categories of psychoactive drugs?

Answer 14

stimulants
depressants
analgesics
hallucinogens
- all can have euphoric effects by impacting the body’s reward system

Question 15

stimulants

Answer 15

increases neural activity / bodily functions

Question 16

depressants

Answer 16

decreases neural activity / bodily functions

Question 17

analgesics

Answer 17

pain relief

Question 18

hallucinogens

Answer 18

cause hallucinations

Question 19

what is direct interference?

Answer 19

associated with receptor binding site

Question 20

direct agonist

Answer 20

mimics the action of the NT, binds to receptor and opens the channel

Question 21

direct antagonist

Answer 21

prevents NT action, blocks receptor and does not open the channel

Question 22

what is indirect interference?

Answer 22

interferes with NT availability
- produce, release or remove NTs

Question 23

indirect agonist

Answer 23

increases availability of a NT by increasing production or preventing reuptake, more likely that a gate will open

Question 24

indirect antagonist

Answer 24

decreases availability of a NT by disrupting production process, makes it less likely that a gate will open

Question 25

in the CNS, how do axons travel to a target structure?

Answer 25

via a tract

Question 26

in the PNS, how do axons travel to a target structure?

Answer 26

via a nerve

Question 27

anatomical pathway

Answer 27

in the visual pathway, signals originate in the retina & are relayed to the LGN to be passed to the primary visual cortex

Question 28

chemical pathway

Answer 28

dopaminergic pathway uses dopamine through all stages (same NT)