在红藻氨酸诱导的大鼠海马癫痫中，NMDAR2上调先于苔藓纤维发芽。

NMDAR2 upregulation precedes mossy fiber sprouting in kainate rat hippocampal epilepsy.

作者信息

Mikuni N, Babb T L, Chakravarty D N, Hadam J L, Penrod C E

机构信息

Department of Neurosciences NC-30, The Cleveland Clinic Foundation, OH 44195, USA.

出版信息

Neurosci Lett. 1998 Oct 9;255(1):25-8. doi: 10.1016/s0304-3940(98)00704-6.

DOI:10.1016/s0304-3940(98)00704-6

PMID:9839718

Abstract

Following intrahippocampal (hilar) kainic acid (KA) lesions in rats, NMDAR2A/B receptor proteins are upregulated significantly in the inner molecular layer (IML) of the dentate gyrus by post-injection day 5. By contrast, the aberrant mossy fibers which reinnervate the IML remained in the subgranular zone before sprouting and synapsing in the IML, which occurs at approximately post-KA day 17. For 40 days thereafter, this mossy fiber ingrowth progressed, while the increased NMDAR2A/B (receptors) immunoreactivity remained at the same densities. These results suggest that new NMDAR2A/B proteins in granule cell dendrites are limited to the IML, which is the eventual site for MF hyperinnervation, neosynaptogenesis, and recurrent synaptic hyperexcitability.

摘要

在大鼠海马内（齿状回门区）注射 kainic acid（KA）造成损伤后，到注射后第 5 天，NMDAR2A/B 受体蛋白在齿状回内分子层（IML）中显著上调。相比之下，重新支配 IML 的异常苔藓纤维在 IML 中发芽和形成突触之前，一直停留在颗粒下区，这大约发生在 KA 注射后第 17 天。此后 40 天，这种苔藓纤维向内生长持续进行，而增加的 NMDAR2A/B（受体）免疫反应性保持在相同密度。这些结果表明，颗粒细胞树突中的新 NMDAR2A/B 蛋白仅限于 IML，而 IML 是苔藓纤维过度支配、新突触形成和反复性突触过度兴奋的最终部位。