title: Acute ipsilateral hyperalgesia and chronic contralateral hypoalgesia after unilateral 6-hydroxydopamine lesions of the substantia nigra.
abstract: The effect of unilateral 6-hydroxydopamine lesions on flinch-jump thresholds to footshock was investigated during 3 months postoperative in rats. Preoperatively, the ipsilateral-contralateral thresholds were closely matched but postoperatively the flinch-jump thresholds to footshock applied to the body surface contralateral to the lesion hemisphere increased, whereas ipsilateral thresholds decreased. The ipsilateral decrease in threshold was maximal at postoperative day 1 but the contralateral increase persisted throughout testing. In control rats no ipsilateral-contralateral differences in the threshold were obtained. In both the control and 6-hydroxydopamine-treated groups there was an additional bilateral decline in jump threshold during the course of the experiment. These results suggest a role for dopaminergic and nondopaminergic participation in an animal's response to nociceptive stimulation.
authors.forename: R J
authors.initials: RJ
authors.lastname: Carey
mesh_terms: D000818:Animals; D004056:Differential Threshold; D004298:Dopamine / Q000502:physiology; D004597:Electroshock; D004924:Escape Reaction; D005528:Foot; D006892:Hydroxydopamines; D008297:Male; D009619:Nociceptors / Q000502:physiology; D016627:Oxidopamine; D010146:Pain / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013378:Substantia Nigra / Q000502:physiology*
chemical_list: D006892:Hydroxydopamines; D016627:Oxidopamine; D004298:Dopamine