Electrical stimulation of the PAG
A) produces changes in sensations of touch and pressure.
B) produces a type of analgesia that is not blocked by naloxone.
C) activates dopamine cells in the medulla, which in turn inhibit spinal cord pain transmission.
D) most likely releases endogenous opiates that act on μ- and κ-receptors.

Question

Quizplus · Accepted Answer

Electrical stimulation of the PAG is known to produce analgesia, and this effect is likely due to the release of endogenous opiates that act on μ- and κ-receptors. This analgesic effect is not blocked by naloxone, which suggests that it is not mediated by exogenous opioids. The PAG also projects to the medulla, where it activates dopamine cells that in turn inhibit spinal cord pain transmission. However, this mechanism is not directly related to the analgesic effect of PAG stimulation.

Electrical Stimulation of the PAG