Limbic seizures increase pronociceptin mRNA levels in the thalamic reticular nucleus

WE studied pronociceptin gene expression following limbic seizures. Norther n blot analysis revealed increased pronociceptin mRNA levels in the thalamu s (but not in the hippocampus) 3-24h after kainate administration, with max imal effect (2-fold increase over basal levels) reached at 6h. No variation in pronociceptin mRNA levels was observed 1-6h after a stimulus-evoked kin dled seizure. Carrageenan failed to affect pronociceptin gene expression in the thalamus, indicating that pain and/or acute stress do not account for kainate effects. In situ hybridization revealed that kainate evokes a drama tic (4-fold) increase in pronociceptin mRNA levels over the thalamic reticu lar nucleus. Kindled seizures evoked only a small, nonsignificant increase in pronociceptin gene expression over the dentate gyrus of the hippocampus. (C) 1999 Lippincott Williams & Wilkins.