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Flashcards in Basal Ganglia Drugs Deck (11)
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D1 and D2 Rs

D1 on GABA neurons in striatum that project to direct pathway. Stimulated by DA.
D2 on GABA neurons projecting to indirect. Inhibited by DA



Loss of DAergic neurons from SN, so lose activation of direct pathway and inhibition of indirect


2 Enzymes of DA Synth

Tyrosine hydroxylase converts tyr to Dopa, and Dopa decarboxylase converts Dopa to DA


2 Enzymes of DA Degradation

COMT and MAO. Can switch positions


Carbidopa (what it is and 2 effects)

Inhibitor of Aromatic L-AA decarboxylase, enzyme that converts L-Dopa to DA.
1. Increases drug in circulation bc stays as L-Dopa (form that can cross BBB
2. Reduces side effects bc less exogenous DA in periphery
Overall can lower the dose and have fewer side effects


4 Problems of PD Treatments

Dietary AAs compete w/ L-Dopa for transport from gut to circulation and circ into brain, so don't take w/ meals
GI problems and cardiac problems from periphery, so take w/ carbidopa
Degeneration of neurons continues and effectiveness of LDopa declines


3 Other PD D Drugs

Pergolide: D1 and 2 agonist
Bromocriptine: D2 agonist, restores indirect inhibition
Ropinirole: D2 agonist


Ach in Striatum

M1/M4 stimulate GABAs going to direct, M1 stimulates GABAs going to indirect


3 Ach PD Drugs

Benztropine: AChR antagonist
Trihexyphenidyl: M1 muscarinic R antagonist
Biperiden: M1 R antagonist


Huntington's Disease

Loss of GABAergic neurons in BG. Ones going to indirect pathway loss first so get hyperactivity


2 HD Drugs

Haloperidol - block DA Rs
Dizepam - enhance GABA Rs