Periaqueductal gray (PAG) contains large numbers of _________ receptors.
A) glutamate
B) substance P
C) endorphin
D) serotonin

Question

Quizplus · Accepted Answer

Periaqueductal gray is known to contain large numbers of opioid receptors, which bind to endorphins. This is important because the endorphin system is involved in modulating pain perception and response. Glutamate and serotonin are neurotransmitters that also play a role in pain processing, but they are not specific to the PAG. Substance P is a neuropeptide that is involved in the transmission of pain signals, but it is not a receptor.

Periaqueductal Gray (PAG) Contains Large Numbers of _________ Receptors