A scientist investigating a newly identified receptor in rat cortex determines that it is a metabotropic receptor that regulates membrane-bound K⁺ channels in some cells and inhibits adenylyl cyclase. Based on these findings, the receptor is most likely a(n) A) β-adrenoceptor. B) D₁-like dopamine receptor. C) D₂-like dopamine receptor. D) autoreceptor.

Question

Quizplus · Accepted Answer

The receptor is a metabotropic receptor and inhibits adenylyl cyclase, meaning it activates a G protein-coupled signaling pathway. The D₂-like dopamine receptor is known to activate this type of signaling pathway, while the β-adrenoceptor is known to activate adenylyl cyclase. Autoreceptors typically regulate the release of neurotransmitters and do not necessarily inhibit adenylyl cyclase. K⁺ channels are not associated with any of the other receptors listed. Therefore, the most likely answer is C, D₂-like dopamine receptor.

A Scientist Investigating a Newly Identified Receptor in Rat Cortex