NEUROPHARMACOLOGYMethamphetamine induces cytosolic Ca2+ oscillations in the VTA dopamine neuronsUramura, Kazuhide1,2; Yada, Toshihiko1,3,5; Muroya, Shinji1,2; Shioda, Seiji4; Shiratani, Toshihiro2; Takigawa, Morikuni2Author Information 1Departments of Physiology, Faculty of Medicine, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520 2Departments of Neuropsychiatry, Faculty of Medicine, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520 3Laboratory of Intracellular Metabolism, National Institute for Physiological Sciences, Okazaki 444-8585 4Department of Anatomy, Showa University School of Medicine, Tokyo 142-8555, Japan 5Corresponding Author: Toshihiko Yada and Address: Departments of Physiology, Faculty of Medicine, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520 Acknowledgements: This work was supported by Grants-in-Aid for Scienti(r)c Research from the Ministry of Education, Science, Sports and Culture of Japan (to T.Y. and T.S.). Received 7 December 1999; accepted 27 January 2000 NeuroReport: April 7, 2000 - Volume 11 - Issue 5 - p 1057-1061 Buy Abstract Methamphetamine (METH) induces a schizophrenia-like psychosis. The dopamine neurons in the ventral tegmental area (VTA) have been implicated in schizophrenia and drug abuse. The present study investigated direct effects of METH on VTA dopamine neurons. We treated adult SD rats with METH (5 mg/kg/day) or saline for 7 days, isolated single VTA neurons, and monitored neurona activities by measuring cytosolic Ca2+ concentration ([Ca2+]i) in immunocytochemically identified dopamine neurons. Acutely administered METH increased [Ca2+]i in dopamine neurons from METH-and saline-treated rats and induced oscillations of [Ca2+]i in dopamine neurons only from METH-treated rats. The METH-induced [Ca2+]i oscillations were inhibited by Ca2+-free conditions and Ca2+ channel blockers. The results indicate that acute METH increases [Ca2+]i in VTA dopamine neurons and that subchronic METH treatment sensitizes them to this drug, resulting in induction of [Ca2+]i oscillations. The activation of VTA dopamine neurons may be related to psycho-stimulant effects of METH. © 2000 Lippincott Williams & Wilkins, Inc.