Raphe and periaqueductal gray induced suppression of non-nociceptive neuronal responses in the dorsal column nuclei and trigeminal sub-nucleus caudalis.

Electrical stimulation of the feline periaqueductal gray matter and nucleus raphe magnus was found to inhibit the firing of trigeminal sub-nucleus caudalis nociceptive neurons, as has been previously reported. However, stimulation at these same sites using similar current intensities was also found to be equally effective in inhibiting the responses of non-nociceptive neurons in both nucleus caudalis and in the dorsal column nuclei.