Cell proliferation and survival in the vestibular nucleus following bilateral vestibular deafferentation in the adult rat.

Cell proliferation and neurogenesis in the brainstem vestibular nucleus complex (VNC) has previously been reported following unilateral vestibular neurectomy in the cat. In this study, we examined the rate of cell proliferation and survival in the adult rat VNC following bilateral vestibular deafferentation (BVD), using injections of bromodeoxyuridine (BrdU) and stereological cell counting. We measured cell proliferation at 24, 48, 72 h and 1 week following BVD and found that it was significantly greater than in sham controls (P=0.002) and that it varied significantly over time (P=0.01), peaking at 48 h in the BVD group. Of note was that sham surgery was also associated with an increase in cell proliferation, which changed over time. When we compared the survival of new cells at 1 month after BrdU injection, there was no significant difference in survival between the sham and BVD groups. These results raise questions about the potential functional significance of cell proliferation in the VNC following vestibular lesions.