CHANGES OF EXPRESSION OF CALCITONIN GENE -RELATED PEPTIDE IN THE RAT TRIGEMINAL MOTOR NUCLEUS AFTER MANDIBULAR NERVE TRANSECTION / 神经解剖学杂志

ABSTRACT

The purpose of this study was to investigate the changes of calcitonin gene-related peptide (CGRP) expression in the trigeminal motor nucleus (Vmo) following mandibular nerve transection. The expression of CGRP and glial fibrillary acidic protein (GFAP) were detected at 3, 7, 14, 21, 28, 35 and 42 days post-axotomy (dpa) by using immunohistochemical and double-immunofluorescence histochemical methods. And the number of CGRP-positive surviving motoneurons was examined by using image analysis system. The present results showed that there was a "biphasic" up-regulation of CGRP-immunoreactivity at 3 and 35 dpa on the ipsilateral side of the Vmo, and significant changes were also observed on the contralateral side. Quantitative analysis revealed that there was almost no loss of motoneurons in the Vmo but there was an evident increase in GFAP expression around the Vmo neurons on the ipsilateral side after axotomy. The present results suggest that the up-regulation of CGRP may exert its trophic effects in both the acute stress reaction and the recovery of the injured motoneurons, and the activated astrocytes may be well involved in this process.