You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Basic Research I1 Apr 2015MP8-17 HIPPOCAMPAL MICROSTIMULATION OR MICROINJECTION OF NMDA IONOTROPIC GLUTAMATE RECEPTOR ANTAGONIST INHIBITS MICTURITION REFLEX IN URETHANE-ANESTHETIZED RATS Yosuke Matsuta, Satoshi Yokoi, Bing Shen, James R. Roppolo, William C. de Groat, Changfeng Tai, and Osamu Yokoyama Yosuke MatsutaYosuke Matsuta More articles by this author , Satoshi YokoiSatoshi Yokoi More articles by this author , Bing ShenBing Shen More articles by this author , James R. RoppoloJames R. Roppolo More articles by this author , William C. de GroatWilliam C. de Groat More articles by this author , Changfeng TaiChangfeng Tai More articles by this author , and Osamu YokoyamaOsamu Yokoyama More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.284AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Recent brain imaging studies reported the activation of hippocampus during micturition, suggesting the involvement in the micturition reflex pathway. The purpose of this study is to investigate the effect of direct stimulation of hippocampus, and to specify the neurotransmitter in the hippocampus involved in the micturition reflex. METHODS A total of 22 female Sprague-Dawley rats weighing 300g under urethane anesthesia (1.2 g/kg) were used in this study. The bladder was cannulated using a PE-50 catheter, and isovolumetric bladder contractions were recorded. A concentric bipolar electrode was inserted stereotaxically and an electrical stimulation (20 Hz frequency, 0.2 ms pulse width and 10–20 V) was applied to the dorsal areas of hippocampus to evaluate its effect on isovolumetric bladder contraction. In 7 rats, the effect of vehicle or MK-801, a NMDA ionotropic glutamate receptor antagonist, microinjected into the hippocampus was investigated. Intercontraction interval, contraction duration and amplitude were compared before and after stimulation or drug administration. RESULTS The stimulation to each side of hippocampus suppressed isovolumetric bladder contraction, and this inhibition lasted for a much longer time than the duration of stimulation. The stimulation significantly increased intercontraction interval, however, it did not significantly change contraction amplitude after the stimulation (Figure 1). The microinjection of MK-801 (1–10 µg) into the hippocampus significantly suppressed isovolumetric bladder contraction (Figure 2). CONCLUSIONS These results indicate that electrical activation of the neurons in hippocampus inhibits the micturition reflex. The antagonism of NMDA glutamate receptor also suppressed micturition reflex, suggesting the involvement of glutamatergic pathway. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e79 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Yosuke Matsuta More articles by this author Satoshi Yokoi More articles by this author Bing Shen More articles by this author James R. Roppolo More articles by this author William C. de Groat More articles by this author Changfeng Tai More articles by this author Osamu Yokoyama More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...