Excitatory effects of XXXX on nociceptive neurons in the medial thalamus.

@entity39278 @entity2951 @entity9563 @entity1510 @entity1286 @entity1812 @entity158 @entity468 @entity38853
Effects of @entity2951 and @entity39278 , which are pungent substances contained in Capsicum annuum L., were studied in 32 @entity9563 immobilized @entity468 . Single units were recorded from the medial thalamus using stainless steel microelectrodes. Of the 56 neurons recorded, 28 were responsive to both noxious (pinching) and non-noxious (hair and/or tapping) stimuli, while 16 were activated only by non-noxious stimuli. The remaining 12 neurons did not respond to any natural stimulus. Somatic receptive fields of nociceptive and non-nociceptive neurons were found to be widely distributed over the whole body. Twenty-six of 28 nociceptive neurons were activated by an intra-arterial administration of @entity1812 , @entity2951 and @entity39278 . Fourteen of 16 non-nociceptive neurons were not activated by these substances. The mean latency and duration of @entity1812 were 8.7 and 12.5 sec, those of @entity2951 were 1.2 and 6.1 sec and those of @entity39278 were 1.3 and 5.0 sec, respectively. The increase of firing frequency produced by @entity2951 and @entity39278 was inhibited by @entity1286 and this inhibition was antagonized by @entity1510 . However, the activity of medial thalamic neurons with non-noxious stimuli was not affected by these drugs. These results suggest that the @entity158 -conducting fibers were selectively activated by @entity38853 as well as by @entity1812 .
