GABAergic projection from brainstem to cerebellar cortex in GAD67ª²GFP transgenic mouse

    LIAO Heng, WANG Zhiª²Ming, WANG Wen, CHEN Tao£¬WU Shengª²Xi, LI Yunª²Qing

    K. K. Leung Brain Research Centre, Department of Anatomy, School of Basic Medicine, Fourth Military Medical University, Xi¬ðan 710033, China, Department of Otolaryngology, PLA 451 Hospital, Xi¬ðan 710054, China

    ¡¾Abstract¡¿ AIM: To observe the distribution of ¦Ãª²aminobutyric acid (GABA)ª²containing neurons projecting to cerebellar cortex from the brainstem of the mouse. METHODS: Doubleª²labeling method using tetramethylª²rhodamine (TMR) retrograde tracing combined with green fluorescent protein (GFP) immunohistochemical staining was utilized to observe the neurons under the laser scanning confocal microscope. RESULTS: TMR retrogradely labeled neurons were mainly found in nucleus of spinal tract of trigeminal nerve (SP5), superior vestibular nucleus (SuVe), spinal vestibular nucleus (SpVe), medial vestibular nucleus (MVe), lateral vestibular nucleus (LVe), ventral cochlear nucleus (VC), dorsal cochlear nucleus (DC), lateral superior olivary nucleus (LSO), principal nucleus of inferior olive (IOPr), medial nucleus of inferior olive (IOM) and dorsal nucleus of inferior olive (IOD). GFPª²like immunoreactive (LI) neurons were mainly observed in SuVe, MVe, LVe, DC, LSO, VC, SP5, SpVe, IOPr, parvocellular reticular nucleus (PCRt) and gigantocellular reticular nucleus (Gi). A few GFPª²LI neurons were also found in the IOM and IOD. TMR/GFP doubleª²labeled neurons were mainly located in SuVe, MVe, LVe, DC, VC, SP5, SpVe and IOPr. Some TMR/GFP doubleª²labeled neurons were also observed in IOM and IOD. CONCLUSION: GABA ergic neurons projecting to the cerebellar cortex are widely located in the brainstem. These GABAergic neurons are probably involved in the coordination and integration of cerebellum for locomotion. ......