Immunohistochemical Study on β1- and β2-Adrenergic Receptors in Rat Vestibular Nuclei

Abstract

Background and Objectives: The aim of this study was to examine the localizations of β1- and β2-adrenergic receptors (ARs) in rat vestibular nuclei by immunohistochemical staining procedure. Materials and Methods: Twelve male Sprague-Dawley rats were used in this study. Primary antibodies for the β1- and β2-ARs were used. The sections were treated with a biotinylated goat anti-rabbit antibody. The sections were then incubated in avidin-biotin-peroxidase reagent and processed with immunoperoxidase using 3.3’-diaminobenzidine tetrahydrochloride. Results: β1-AR and β2-AR 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. β1-AR and β2-AR were moderately expressed in the superior vestibular nucleus, lateral vestibular nucleus, medial vestibular nucleus,and spinal vestibular nucleus. Conclusion: The present study demonstrates, for the first time, that β1-AR and β2-AR receptors are localized in rat vestibular nuclei. Furthermore, this study may provide additional speculation into the role of ARs during vestibular signal processing. Further studies are needed to clarify the roles played by β1-ARs and β2-ARs through physiologic and functional studies.