Temporal changes of Glutamate release in the medial vestibular nucleus following unilateral laby-rinthectomy in conscious rats

【作者】 刘思源； 卢焕俊； 金元哲； 李香兰；

【Author】 Department of Physiology and pathophysiology,Yanbian University College of Medicine;

【机构】 Department of Physiology and pathophysiology,Yanbian University College of Medicine；

【摘要】 To understand the neurochemical mechanism underlying the vestibular compensation,we determined the levels of glutamate following unilateral labyrinthectomy(UL)by using in vivo brain microdialysis and high-performance liquid chromatography(HPLC)technique.Rats were pretreated by infusing 10 mg arsanilic acid into the tympanic cavity to obstruct uni-periphery vestibular organ,and then the changes of glutamate release from the ipsi-and contra-lesional medial vestibular nucleus(MVN)following UL were investigated in conscious rats.The concentration of glutamate in the ipsi-lesional MVN,which increased until UL 12h,after which the release did not show any change between 12 and 48 h post-UL,decreased gradually to the basal level until 48-144 h post-UL followed by no further change.In contrast,the concentration of glutamate in the contra-lesional MVN,which increased immediately after UL 2 h,decreased gradually to the basal level until 6-12 h post-UL,after which the release did not show any change between 12 and 24 h post-UL,and then increased significantly between 24 and 72 h post-UL,decreased gradually to the basal level until 72-144 h post-UL followed by no further change.Thedifference in the glutamate concentration between ipsi-and contra-lesional MVN increased immediately after UL and gradually decreased accompanied by a reduction in the frequency of nystagmus.These result suggest that the imbalance of glutamate release between bilateral nuclei induced the nystagmus,and the change in release is concerned with the rapid development of vestibular compensation.更多还原

【Abstract】 To understand the neurochemical mechanism underlying the vestibular compensation,we determined the levels of glutamate following unilateral labyrinthectomy(UL) by using in vivo brain microdialysis and high-performance liquid chromatography(HPLC) technique.Rats were pretreated by infusing 10 mg arsanilic acid into the tympanic cavity to obstruct uni-periphery vestibular organ,and then the changes of glutamate release from the ipsi-and contra-lesional medial vestibular nucleus(MVN) following UL were investigated in conscious rats.The concentration of glutamate in the ipsi-lesional MVN,which increased until UL 12 h,after which the release did not show any change between 12 and 48 h post-UL,decreased gradually to the basal level until 48-144 h post-UL followed by no further change.In contrast,the concentration of glutamate in the contra-lesional MVN,which increased immediately after UL 2 h,decreased gradually to the basal level until 6-12 h post-UL,after which the release did not show any change between 12 and 24 h post-UL,and then increased significantly between 24 and 72 h post-UL,decreased gradually to the basal level until 72-144 h post-UL followed by no further change.Thedifference in the glutamate concentration between ipsi-and contra-lesional MVN increased immediately after UL and gradually decreased accompanied by a reduction in the frequency of nystagmus.These result suggest that the imbalance of glutamate release between bilateral nuclei induced the nystagmus,and the change in release is concerned with the rapid development of vestibular compensation.更多还原