Baclofen acts as -: (A) GABAA receptor agonist, (B) GABAB receptor agonist, (C) GABAA receptor antagonist, (D) GABAB receptor antagonist
Answer is B. Ans. is 'b' i.e., GABAB receptor agonist There are two types of GABA receptors. 1. GABAA receptor - Intrinsic ion channel --> increases Cl- conductance, blocked by bicuculline, facilatated by benzodiazepines. 2. GABAB receptor - G protein coupled receptor; hyperpolarizes neurones by increasing IC conductance and altering Ca' flux, bicuculline has no effect, blocked by saclofen. o Baclofen acts as an agonist on GABAB receptor.