Which is not a metabotrophic receptor?

(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.