|
KMID : 0355519920160010013
|
|
Korean Journal of Oral Biology
1992 Volume.16 No. 1 p.13 ~ p.24
|
|
|
Pain Control Mechanism in Brainstem-Role of Catecholaminergic and GABergic Neurones
|
|
Yum Kwang-Won
Lee Song-Heun
Kim Joong-Soo
|
|
|
Abstract
|
|
|
|
This study was carried out to clarify the role of locus coeruleus(LC), periaqueductal gray(PAG), catecholaminergic and GABAergic neurones on the descending pain modulation of brainstem. Under light general anesthesia, anterior digastric EMG as jaw opening reflex evoked by noxious electrical stimuli and extracellular neural activity of medullary dorsal horn responded to mechanical stimuli applied to facial skin were recorded to evaluate the effect of conditioned-stimulation of PAGand LC, respectively. Muscimol and bicuculline were injected into cerebral ventricle with microsyringe and the effects of drugs and conditioned --stimulation of PAG were determined by per cent change of amplitude of digastric EMG and compared in normal, 6-hydroxydopamine(OHDA)-treated and 5.7-dihydroxytryp-tamine (DHT)-treated animal. Conditioned-stimulation of LC had inhibitory effect on the jaw opening reflex evoked by noxious stimuli and inhibited the neural activity of nociceptive neurones responded to noxious mechanical stimuli. Muscimol inhibited the jaw opening reflex evoked by noxious stimuli and enhanced the inhibitory effect of PAG on jaw opening reflex in normal animal, but effects of muscimol and PAG decreased in 6-OHDA-treated animal and increased in 5.7-DHT-treated animal. Bicuculline partially blocked the effect of muscimol.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|