lecture 5 Flashcards
schizophrenia
hallucinations, delusions, disorganised thought and emotional dysfunction
parkinsons disease
movement disorder
trembling, slowness, rigidity, problems initiating voluntary movements
therapy for schizophrenia
antipsychotic drugs
side effects of drugs for schizophrenia
Parkinsonism
therapy for Parkinson’s disease
l-dopa - precursor of dopamine
possible side effects of drugs for Parkinson’s
psychotic disorder
acetylcholine
activates muscle fibre - muscle contraction
dopamine
voluntary movement , action planning, control
noradrenalin
increases vigilance and readiness to act
serotonin
calming , reduces impulsive behaviour
NT can bind to a
range of specific receptors
at different synapses
the same NT can have different effects
neurotransmitter synthesis
NT’S are often complex molecules that cannot be stored in large amounts
need to be constantly synthesised
drug
a substance that even in small quantities has major effects on bodily functions
psychoactive drug
a drug that affects the CNS and alters alertness, perceptual , cognitive and emotional processes
all psychoactive drugs
interfere with the brains neurotransmitter systems
four functional categories
stimulants, depressants , analgesics , hallucinogens
stimulants
increase neural activity or bodily functions
depressants
decrease neural activity or bodily functions
analgesics
relieve pain
hallucinogens
cause hallucinations
all of these have strong
euphoric effects - create a sense of intense well being
direct interference - post synaptic receptor sites
are specific to NT molecular structure
agonists DIRECT
mimic action of their NT- bind to receptor and open channel
antagonists DIRECT
prevent action of their NT
block the receptor - no NT bind but don’t open the channel
indirect interference
interfere with production , release, removal of NT’S
agonists INDIRECT
increase availability of NT
increase production or prevent reuptake
making it more likely that the gate will open
antagonists INDIRECT
decrease availability of NT
Disrupt production processes- making it less likely that the gate will open
why do drugs produce systematic effects - not random ones
neurons are not distributed randomly- they form systematic , anatomical pathways
two ways to identify pathways
anatomically and chemically
anatomically
nigro- striatum pathway
begins in the substantial nigra and ends in the striatum
starting to end point
chemically
dopaminergic pathway
uses dopamine throughout all stages
dopaminergic nigro striatum pathway
involved in motor control
dopaminergic meso limbic cortical pathway
involved in emotion , memory , planning and control
schizophrenia is associated with
over activity in the mess limbic cortical pathway
too much dopamine/ hypersensitive dopamine receptors
parkinsons disease
caused by degeneration of the substantia nigra
under activity in the NS pathway
lack of dopamine
treatment for schizophrenia antipsychotic drugs-
dopamine antagonists- meso limbic cortical system returns to normal levels of activity
psychopharmacology
why can’t we target the drug to stay in one pathway
target structures differ in distribution of dopamine receptor subtypes
