Auditory nerve input is not an absolute requirement for the expression, distribution and calcium permeability of AMPA receptors in the adult rat ventral cochlear nucleus

详细信息	查看全文 | 推荐本文 |

• 作者：Juan Ramon Martinez-Galan ; Elena Caminos ; Carmen Vale ; Jose M. Juiz
• 关键词：Deafferentation ; Glutamate receptor ; AMPA ; Auditory system ; Cochlear nuclei
• 刊名：Brain Research
• 出版年：2007
• 期刊代码：8_00068993
• 类别：neu
• 出版时间：23 March 2007
• 卷：1138
• 期：Complete
• 页码：21-29
• 文件大小：869 K

摘要

In order to understand whether glutamatergic excitatory presynaptic input is an absolute requirement for the adult regulation of postsynaptic glutamate receptors we analyzed if a period of 11 days of excitatory deprivation affects the expression, distribution and Ca²⁺ permeability of AMPA receptor subunits in the ventral cochlear nucleus of the rat. Bilateral cochlear ablations were performed in 30-day-old rats. After 11 days of survival, immunohistochemistry for GluR1, GluR2/3 and GluR4 AMPA receptor subunits showed no changes in the normal pattern of distribution, with GluR2/3 and GluR4 immunoreactivity predominating, and little GluR1. No changes in the amount of these AMPA receptor subunits were found between normal and cochleotomized rats in Western blots. AMPA receptors lacking the GluR2 subunit are Ca²⁺ permeable. Kainate-induced Co²⁺ uptake histochemistry, which labels AMPA Ca²⁺ permeable receptors, demonstrated no changes in somatic labeling intensity for Co²⁺, 11 days after cochleotomy. Therefore, our data indicate that excitatory input is not an absolute requirement to maintain AMPA receptor subunit expression, distribution and functional properties such as Ca²⁺ permeability in VCN neurons. Nevertheless, subtle changes in AMPA receptors through regulatory post-transductional mechanisms cannot be ruled out.