Dopamine Flashcards
monoamines share a common what
single amine functional group
what are the 3 catecholamines
epinephrine, norepinephrine and dopamine
is serotonin a catecholamine, a monoamine or both
monoamine
true or false - the enzymes in the formation fo dopamine are rate limiting
true
what is VMAT
transporter that loads dopamine into vesicles
what inhibits VMAT
reserpine
reserpine causes _____ in animals and ______ in humans
sedation/depression
what are the 2 pathways to making homovanillic acid
- DA + MAO -> DOPAC + COMT -> HVA
- DA + COMT -> 3-MT + MAO -> HVA
what are the 3 things that occur when cocaine and amphetamines inhibit DAT reuptake
- increases dopamine in the syanpse
- prolong dopamine signaling
- hyperactivity of DA circuits
the presynaptic terminal of a dopaminergic synapse is rich in what 3 enzymes
TH, DOPA and decarboxylase
is D1 family associated with excitatory or inhibitory features
excitatory
Gs alpha does what
increases cAMP
Gi alpha does what
decreases cAMP
what kind of receptors are D1 and D2
G-coupled receptors
where does dopamine synapse
on the neck of dendritic spines
what are the 3 dopaminergic pathways
nigrostriatal, tuberoinfundibular, mesolimbic
what are the projections of the nigrostriatal system
from substantia nigra and ventral tegmental area to striatum
in the mesolimbic system, there are projections from the ventral tegmental area to what
limbic system and nucleus accumbens
true or false - 6-OHDA is permeable to the BBB
false - it cannot cross the BBB
what is 6-OHDA
a selective neurotoxin
what are the outcomes of a bilateral nigrostriatal lesion
sensory neglect and motor impairment
what are the outcomes of a unilateral lesion
postural asymmetry and turning
what is MPTP
a neurotoxin that depletes dopamine -> parkinson symptoms
true or false - MPTP is resisant to L-DOPA treatment
true
why could there be too much D1 and D2 receptors in the basal ganglia , what is the outcome
when there is no dopamine to activate the receptors, they just stay there and therefore no movement can be initiated properly
DAT knockout causes hyper or hypoactivity
hyperactivity
what drug has similar effects to the DAT knockout
cocaine
____ receptor knockout removes the effects of cocaine on hyperactivity
D1
what are the main functions of nucleus accumbens
modifies awareness of information flow in addictions and psychosis
limbic connections mediate what 3 things
memory, learning and affect
hyperactivity in the mesolimib system leads to positive/negative symptoms
positive
list examples of positive symptoms
delusions, hallucinations, disorganized speech, catatonic motor actions
list examples of negative symptoms
social deficits, cognitive deficits and avolition
what can excess dopamine in the nucleus accumbens leads to what in patients
perceive voices, sounds and imagery
in schizophrenia patients, explain the process of dopamine at the nucleus accumbens and compare to healthy people
in healthy people -> information important, dopamine will be sent to the NA
in schizophrenia patients -> information that is not important will come through which is associated with excess dopamine at the NA
what are the two common antipsychotics that inhibit D1 and D2
chlorpromazine and haloperidol
antipsychotic efficacy is correlated with ______
D2 binding
match the definition to the term
inability to initiate movement
akinesia
match the definition to the term
inability to remain motionless
akathisia
match the definition to the term
fixed parkinsonism without degeneration of dopamine
pseduoparkinsonism
what are some symptoms of hyperprolactinaemia
spontaneous lactation, sexual dysfunction and infertility
schizophrenia patients have the highest comorbidity with which addiction , second highest?
first -> nicotine abuse
second -> alcohol and drug abuse
early aubstance abuse correlates with what
schizophrenia onset and severity
what is a frequent reason for the first episode of psychosis
cannabis and amphetamine intoxication
reduced D2/3 binding correlates with what
high impulsivity and addictive behavior
true or false - impulse control is a component of executive function
true
