Cannabinoid CB2 receptor expression in the rat brainstem cochlear and vestibular nuclei

Conclusion. This evidence suggests that both CB1 and CB2 receptors are important in the control of balance and hearing. Objective. Although the cannabinoid CB1 receptor has been identified in the brainstem vestibular and cochlear nuclei, the existence of the second cannabinoid receptor subtype, the CB2 receptor, has been more controversial. The aim of this study was to determine whether or not CB2 receptors are expressed in the vestibular and cochlear nuclei. Materials and methods. Data were obtained from four young male Wistar rats In analyzing the presence of CB2 receptors in the vestibular and cochlear nuclei, the immunohistochemical complex was visualized by exposure to diaminobenzidine for 20 min. Positive immunoreactivity to CB2 was expressed as brown staining in the cytoplasm, nucleus, nuclear membrane and cell membrane. Results. We confirmed the existence of the CB2 receptor in the vestibular and cochlear nuclei in the brainstem of Wistar rats.