Cortical involvement in @entity11989 cell hyperactivity and @entity146 in XXXX with dorsal root section.

@entity308 @entity146 @entity5300 @entity35 @entity11989
Experiments were performed on @entity35 using neurophysiological and behavioral techniques, in an attempt to study the role played by the somatosensory cortex in the abnormal spinal neuron activity and @entity146 observed after @entity5300 . The onsets of both phenomena occur at the same postoperative period. Cortical controls exerted on spinal @entity11989 ( @entity11989 ) cells were studied using a transient and reversible cortical blockade, @entity308 ( @entity308 ), applied contralateral to the spinal cord recording. In 28 intact animals, 55 cells were studied during the propagation of at least two CSDs. Only 4 of these cells presented a sustained decrease in their spontaneous activity during @entity308 , which may correspond to transient arrest of a descending tonic cortical facilitation. In 29 animals with dorsal root sections, 161 @entity11989 cells displayed abnormal burst activity, and 52 were examined with the @entity308 test. Thirty-five cells presented a long-duration change in their spontaneous activity during @entity308 ; of these, 28 showed decreased activity (suppression of descending tonic facilitation) and 7 presented increased activity (suppression of descending tonic inhibition). More @entity11989 cells were influenced by the cortex in deafferented @entity35 (67%) than in intact @entity35 (7%). The cortical influence was also stronger, as the hyperactive cells were frequently rendered silent during @entity308 . These observations suggest that the abnormal activity is partly due to a descending cortical influence. Results of a behavioral study performed on 22 @entity35 (one control group and two experimental groups with cortical ablations) showed that the self-mutilating behavior, which develops at the same time as the abnormal @entity11989 cell activity, was reduced by unilateral cortical ablation, independent of the cortical region removed. The possible pathways involved in this cortical influence are examined in the discussion.
