Temporal changes of calbindin expression in the nodulus following unilateral labyrinthectomy in rats.
Following unilateral vestibular deafferentation, many of the oculomotor and postural symptoms, such as spontaneous ocular nystagmus and head tilt, gradually abate over time in a process known as 'vestibular compensation'. Although many experimental studies have indicated a role for the cerebellum during vestibular compensation, the effects of unilateral labyrinthectomy (UL) on cerebellar function and the role of cerebellum in post-lesional plasticity remain unclear. Thus, we investigated the temporal changes of calbindin expression in the ipsilateral and contralateral nodulus to the lesion side during vestibular compensation following UL in rats. Change of calbindin expression in the nodulus was measured by immunohistochemistry at 2, 6, 24 and 48hr following UL. The staining intensity of calbindin-positive Purkinje cells in the ipsilateral and contralateral nodulus to the lesion side was found to decrease 6hr after UL compared with the control and asymmetric calbindin expression between ipsilateral and contralateral nodulus 24hr after UL. Forty-eight hours after UL, calbindin expression returned to the control level, and asymmetric expression in both noduli also subsided. It is suggested that the regulation of calbindin expression may facilitate synaptic plasticity by adjusting the efficacy of biochemical responses of Purkinje cells according to the changes in neuronal activity in the vestibular nuclear complex during the early phase of vestibular compensation. Thus, the results revealed that the nodulus has a role during vestibular compensation through Purkinje cells.
Department of Physiology, Wonkwang University School of Medicine and Brain Research Institute at Wonkwang University, Iksan 570-749, Republic of Korea.
Byung Rim
BR
Park
Myoung Ae
MA
Choi
Seok Min
SM
Hong
D000344:Afferent Pathways; D000818:Animals; D064026:Calbindins / Q000378:metabolism*; D002531:Cerebellum / Q000378:metabolism*; D003714:Denervation; D007758:Ear, Inner / Q000294:innervation*; D007395:Interneurons / Q000378:metabolism; D008297:Male; D011689:Purkinje Cells / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D064026:Calbindins
Calbindin; Nodulus; Purkinje cell; Rat; Vestibular compensation