lecture 7 Flashcards
(26 cards)
dopamine
primary rewards, treatment parkinsons, schizophrenia, attention deficit disorder and drug dependence
in the brain
neurotransmitter, neuromodulator
in the periphery
local chemical messenger
in blood vessels
it inhibits noradrenaline release and acts as a vasodilator
in the kidneys
it increases sodium excretion urine output
in the pancreas
it reduces insulin production
in the digestive system
it reduces GI motility and protects intestinal mucosa
in the immune system
it reduces the activity of lymphocytes
carbidopa
DOPA-decarboxylase inhibitor. indicator for Parkinsons disease
levodopa
treatment of Parkinsons, can cross blood brain barrier
COMT
can metabolise dopamine
MAO
can metabolise dopamine together with COMT into various compounds to eventually from HVA
MAO-A
expressed in the CNS, anti-depressants
MAO-B
expressed in liver and peripheral organs, more specific for dopamine, important in parkinsons disease
tranylcypromine
active metabolite irreversibly inhibits MAO-A and MAO-B
nigrostriatal pathway
75% brain dopamine, substantia nigra (cell body), corpus striatum (axon), parkinsons
mesolimbic pathway
midbrain VTA, amygdaloid nucleus (axons), more on behaviour (schizophrenia)
mesocortical pathway
midbrain VTA, frontal cortex (axons)
tuberohypophyseal pathway
ventral hypothalamus, pituitary gland (axons)
Type 1 dopamine receptors
D1, D5, coupled to Gs, dopamine activation leads to increase in cAMP and PKA activation
Type 2 dopamine receptors
D2, D3, D4, coupled to Gi, binding of dopamine leads to decrease in cAMP and increased K+ channel conductivity
motor control
nigrostriatal system
behavioural aspects
mesolimbic and mesocortical system
endocrine control
tuberohypophyseal system
