This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Medicine
[{'content': 'Which is not a metabotrophic receptor? \nSelect and explain. \nA. GABA receptor, B. b receptor for NA, C. Acetylcholine receptor, D. a receptor for NA', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (B) b receptor for NA # Glutamate receptors are of two types: metabotropic receptors and ionotropic receptors.> The metabotropic receptors are serpentine G protein-coupled receptors that increase intracellular IP3 and DAG levels or decrease intracellular cAMP levels. Eleven different subtypes have been identified.> They are both presynaptic and postsynaptic and both are widely distributed in the brain.> They appear to be involved in the production of synaptic plasticity, particularly in the hippocampus and the cerebellum.> Examples of metabotrophic receptors include Glutamate Receptors, Muscarinic Acetyl choline receptors, GABA (3 receptors and omst serotonin receptors, as well as receptors of norepinephric, epinephrine, histamine, Dopamine, neuropeptides and endocannabinoids.> Knockout of the gene for one of these receptors, one of the forms of mGluRI, causes severe motor incoordination and deficits in spatial learning.> The ionotropic receptors are ligand-gated ion channels that resemble the nicotinic cholinergic receptors and the GABA and glycine receptors.', 'role': 'assistant'}]