ABSTRACT
Objective To explore the role and mechanisms of 5-HT1Areceptors in the medial septum-diagonal band of Broca complex (MS-DB) in hemiparkinsonian rats. Methods Combined behavioral and electrophysiological studies were performed to assess the role of MS-DB 5-HT1Areceptors in working memory and hippocampal theta rhythm in rats with 6-hydroxydopamine (6-OHDA)lesions in the medial forebrain bundle (MFB).Results ① MFB lesions in the rats decreased choice accuracy in the T-maze rewarded alternation test. Intra-MS-DB injection of 5-HT1Areceptor agonist 8-OH-DPAT further decreased choice accuracy,while intra-MS-DB injection of 5-HT1Areceptor antagonist WAY-100635 increased choice accuracy in the lesioned rats.② MFB lesions in the rats decreased peak theta rhythm frequency. Intra-MS-DB injection of 8-OH-DPAT suppressed hippocampal theta rhythm and decreased normalized theta power,while intra-MS-DB injection of WAY-100635 induced theta rhythm and increased normalized theta power.Conclusion Blockade of MS-DB 5-HT1Areceptors can recover cognitive dysfunction in Parkinson's disease, which may be attributed to the enhancement of hippocampal theta rhythm.