Immunohistochemical and biomolecular identification of melatonin 1a and 1b receptors in rat vestibular nuclei

Abstract

Objective: The aim of this study was to examine the localizations and expressions of melatonin 1a (MT1a) and 1b (MT1b) receptors in rat vestibular nuclei by immunohistochemical staining and reverse transcriptase-polymerase chain reaction. Materials and methods: Twenty male Sprague-Dawley rats were used in this study. Antibodies for the MTla and MT1b receptors were used in 10 rats, respectively. A further 10 animals were sacrificed for RT-PCR. Tissues containing medial vestibular nuclei were selectively isolated from brain stem slices for RT-PCR. Results: MTla and MT1b receptor immunopositive neurons were found to be distributed throughout the four major vestibular nuclei. Both receptors were primarily detected in neuronal somata and their proximal dendrites. The presences of the mRNAs of the MT1a and MT1b receptors were confirmed by RT-PCR in medial vestibular nuclei and trigeminal ganglia. Conclusions: The present study demonstrates, for the first time, that MTla and MT1b receptors are localized and expressed in rat vestibular nuclei. This study provides additional insight into the role of melatonin receptors during vestibular signal processing. (C) 2011 Elsevier Ireland Ltd. All rights reserved.