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Dorsal root potential evoked by stimulation of periaqueductal gray and its efferent pathway analysis in rats

Zhang Ailing, Cheng Zhenfeng

Department of Physiology, Xi'an Medical University. Xi'an, China

Abstract

When periaqueductal gray (PAG) was stimulated with concentric electrodes,
a steady negative potential called PAG-DRP was recorded from L_(5) dorsal root.
PAG-DRP with properties of spatial and temporal summation propagates decre-
mentally along the dorsal root and is inhibited by picrotoxin. Lesions of NRM
had no effect on the PAG-DRP evoked by stimulation of dorsal PAG, but showed
obvious reduction up to about 40% on the PAG-DRP evoked stimulation of ven-
tral PAG. It is suggested that the descending inhibition of PAG includes some
presynaptic inhibition and that the ventral PAG-DRP is relayed partly via NRM
while the dorsal PAG-DRP is not associated with NRM.

Key words: Periaqueductal gray;Nucleus raphe magnus;Spinal dorsal root potential;Presyasptic inhibition

Received: 　　Accepted:

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Citing This Article：

Zhang Ailing, Cheng Zhenfeng. Dorsal root potential evoked by stimulation of periaqueductal gray and its efferent pathway analysis in rats. Acta Physiol Sin 1990; 42 (3): (in Chinese with English abstract).