Which receptor is known to mediate spinal analgesia, delusions, hallucinations, and dysphoria?

The receptor known to mediate spinal analgesia, delusions, hallucinations, and dysphoria is the kappa opioid receptor. This receptor plays a significant role in producing certain effects that can include analgesia, particularly at the spinal level, which contributes to pain relief mechanisms. However, it is also associated with several central nervous system effects such as dysphoria and hallucinations, distinguishing it from other receptors in the opioid system.

Kappa opioid receptors are unique among opioid receptors because their activation can lead to feelings of dysphoria rather than euphoria, which is commonly associated with mu opioid receptor activation. This receptor can also mediate analgesic effects, but it does so with a different side effect profile that includes potential psychological effects.

While the delta opioid receptor and mu opioid receptor also are involved in analgesic processes, their role does not encompass the same breadth of effects—particularly psychotropic ones—associated with kappa receptors. Therefore, understanding the distinct effects attributed to kappa opioid receptors provides clarity regarding their specific contributions to both pain management and adverse psychological reactions.