Role of the deep mesencephalic nucleus in the antinociception induced by stimulation of the anterior pretectal nucleus in rats.
The present study showed that the inhibitory effect on the tail-flick reflex (TF) of stimulating the deep mesencephalic nucleus (DpMe) was very similar to that produced by stimulation of the anterior pretectal nucleus (APtN). An electrolytic lesion of the ipsilateral DpMe greatly reduced the inhibitory effect of APtN stimulation on the TF. Furthermore, activating the neuronal cell bodies in DpMe but not the fibers of passage by microinjection of L-glutamate into this area was also shown to elicit inhibition of TF. On the other hand, inhibiting the neuronal cells in DpMe by microinjection of gamma-aminobutyric acid produced a marked reduction in the APtN-induced inhibition of TF, which was comparable to that produced by DpMe lesions. It is suggested that the APtN-induced antinociception is, at least in part, mediated via a relay through the DpMe.
Research Laboratory of Neurophysiology, Xi'an Medical University, Shaanxi, People's Republic of China.
X M
XM
Wang
B
B
Yuan
Z L
ZL
Hou
D000818:Animals; D004558:Electric Stimulation; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D008636:Mesencephalon / Q000187:drug effects / Q000502:physiology*; D008845:Microinjections; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains; D012018:Reflex / Q000502:physiology*; D013623:Tail / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D005971:Glutamates; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid