This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General, Subject name: Physiology
Ligand-gated ionic channel? 
Select and explain. 
A. VIP receptor, B. GAB AA receptor, C. Norepinephrine receptor, D. GABAB receptor
B: GAB AA receptor
Answer: B: GAB AA receptor 
Explanation: Ans. b (GABAA receptor) (Ref. Ganong Physiology 22nd/Chapter 1 and Fig. 1-29)Receptor with Intrinsic Ion Channel: 1. GABA-A, 2. Nicotinic cholinergic, 3. NMDA, and 4. 5-HT3 receptors.GABA receptors LocationDrugs which bind them GABA-A receptorNeuronal membranes in CNSBenzodiazepinesBarbituratesZolpidem and many othersGABA-B receptorsCoupled to G proteins that either inhibit Ca++ channels or activate K+ channelsSelectively activated by Baclofen