[Neuronal and neurochemical mechanisms of hypothalamic inhibition of the pain reflex].
Effect of high-frequency stimulation of medial and lateral areas of the posterior, tuberal and anterior hypothalamus as well as of the periaqueductal gray (PAG) on jaw-opening reflex elicited with tooth-pulp stimulation, was studied in anesthetized cats. The m. digastricus EMG response was suppressed with stimulation of all hypothalamic structures. The threshold of the inhibitory effect was lower in the PAG stimulation. Hypothalamic stimulation-produced antinociception was reversed by the specific opiate antagonist naloxone, effect of PAG stimulation being less sensitive to naloxone. After bilateral lesion of PAG the antinociceptive effect of the hypothalamus was only slightly reduced. Complete inhibition of the EMG nociceptive response, similar to the effect of hypothalamus and PAG stimulation was induced with administration of an opiate agonist phenaridine.
O G
OG
Baklavadzhian
A G
AG
Darbinian
I Kh
IKh
Taturian
N M
NM
Ipekchian
D015761:4-Aminopyridine / Q000031:analogs & derivatives*; D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D002415:Cats; D007031:Hypothalamus / Q000502:physiology*; D009270:Naloxone / Q000494:pharmacology; D010146:Pain / Q000503:physiopathology*; D010487:Periaqueductal Gray / Q000502:physiology; D012018:Reflex / Q000502:physiology*
D000700:Analgesics; D009270:Naloxone; D015761:4-Aminopyridine; C054783:phenaridine
Neĭronnye i neĭrokhimicheskie mekhanizmy gipotalacicheskogo tormozheniia bolevogo refleksa.