This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Pharmacology
[{'content': 'All of the following act through GABA except - \nSelect and explain. \nA. Phenobarbitone, B. Carbamazepene, C. Zopiclone, D. Muscimol', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Carbamazepene Gaba receptorso There are two types of GABA receptorsGABAa receptor - Intrinsic ion channel -increases Cl' conduction.GABAb receptor - G protein coupled receptor - hyperpolarizes neurones by increasing K+ conductance and altering Ca+2 flux.", 'role': 'assistant'}]