PSYCHOBIOLOGY: neurotransmitter pathways Flashcards
what is the general pathway in the brain?
activity follows specific pathways that are symmetrically arranged on both sides of the midline
describe the theoretical implications of brain pathways using Sz & Parkinson’s
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
describe the classification of neurotransmitters based on chemical structure
- amines
- amino acids
- peptide transmitters
- gas transmitters which are synthesised as needed
- they are chemically related because they are complex versions of one another
describe the classification of neurotransmitters based on function
classified based on input / output (glutamate & ACh are excitatory and GABA is inhibitory) and information modulation
function of ACh
- activates cerebral cortex
- facilitates learning
- activates muscle fibres for muscle contraction
function of dopamine
- voluntary movement
- action planning
- control
function of noradrenaline
- increased vigilance & ready to act
function of serotonin
- calming
- reduces impulsive behaviour
why do NTs have to be constantly synthesised?
they are complex molecules which cannot be stored in large amounts
what is a drug?
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
endogenous
substances produced by the body
exogenous
substances which enter the bloodstream from external sources
what is a psychoactive drug?
a drug that affects the CNS & alters alertness, perceptual, cognitive & / or emotional processes
- all interfere with neurotransmitter systems
what are the 4 categories of psychoactive drugs?
stimulants
depressants
analgesics
hallucinogens
- all can have euphoric effects by impacting the body’s reward system
stimulants
increases neural activity / bodily functions
depressants
decreases neural activity / bodily functions
analgesics
pain relief
hallucinogens
cause hallucinations
what is direct interference?
associated with receptor binding site
direct agonist
mimics the action of the NT, binds to receptor and opens the channel
direct antagonist
prevents NT action, blocks receptor and does not open the channel
what is indirect interference?
interferes with NT availability
- produce, release or remove NTs
indirect agonist
increases availability of a NT by increasing production or preventing reuptake, more likely that a gate will open
indirect antagonist
decreases availability of a NT by disrupting production process, makes it less likely that a gate will open
