[Dorsal root potential evoked by stimulation of periaqueductal gray and its efferent pathway analysis in rats].
When periaqueductal gray (PAG) was stimulated with concentric electrodes, a steady negative potential called PAG-DRP was recorded from L5 dorsal root. PAG-DRP with properties of spatial and temporal summation propagates decrementally 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 by stimulation of ventral 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.
Zhang
A L
AL
Department of Physiology, Xi'an Medical University.
Cheng
Z F
ZF
D000818:Animals; D004525:Efferent Pathways / Q000502:physiology; D004558:Electric Stimulation; D005071:Evoked Potentials; D005260:Female; D005727:Ganglia, Spinal / Q000502:physiology; D008297:Male; D010487:Periaqueductal Gray / Q000502:physiology*; D010852:Picrotoxin / Q000494:pharmacology; D011903:Raphe Nuclei / Q000502:physiology; D051381:Rats; D013116:Spinal Cord / Q000502:physiology*; D013569:Synapses / Q000502:physiology
D010852:Picrotoxin