Asako Mikiya, Holt Avril G, Griffith Ronald D, Buras Eric D, Altschuler Richard A
Kresge Hearing Research Institute, Department of Otolaryngology/Head Neck Surgery, University of Michigan, Ann Arbor, Michigan 48109-0506, USA.
J Neurosci Res. 2005 Jul 1;81(1):102-9. doi: 10.1002/jnr.20542.
There is increasing evidence of activity-related plasticity in auditory pathways. The present study examined the effects of decreased activity on immunolocalization of the inhibitory neurotransmitter glycine in the cochlear nucleus of the rat after bilateral cochlear ablation. Specifically, glycine-immunoreactive puncta adjacent to somatic profiles were compared in normal hearing animals and animals deafened for 14 days. The number of glycine-immunoreactive puncta surrounding somatic profiles of spherical and globular bushy cells, glycine-immunoreactive type I stellate multipolar cells, radiate neurons (type II stellate multipolar cells), and fusiform cells decreased significantly. In addition, the number of glycine immunopositive tuberculoventral (vertical or corn) cells in the deep layer of the dorsal cochlear nucleus also decreased significantly. These results suggest that decreased inhibition reported in cochlear nucleus after deafness may be due to decreases in glycine.
越来越多的证据表明听觉通路中存在与活动相关的可塑性。本研究检测了双侧耳蜗切除后,活动减少对大鼠耳蜗核中抑制性神经递质甘氨酸免疫定位的影响。具体而言,比较了正常听力动物和致聋14天的动物中,与体细胞轮廓相邻的甘氨酸免疫反应性斑点。球形和球状浓密细胞、甘氨酸免疫反应性I型星状多极细胞、辐射神经元(II型星状多极细胞)和梭形细胞的体细胞轮廓周围的甘氨酸免疫反应性斑点数量显著减少。此外,耳蜗背核深层的甘氨酸免疫阳性结核腹侧(垂直或角状)细胞数量也显著减少。这些结果表明,耳聋后耳蜗核中报道的抑制作用降低可能是由于甘氨酸减少所致。