Robitaille Y, Sherwin A
J Neuropathol Exp Neurol. 1984 Jul;43(4):376-83.
Cortical astrocytes of normal mammalian brain are endowed with a high affinity uptake system for beta-Alanine which is competitively inhibited by gamma aminobutyric acid (GABA), a neurotransmitter strongly implicated in epileptogenesis. We evaluated (3H) beta-Alanine uptake by reactive astrocytes proliferating within scar of epileptogenic foci induced in rat motor cortex by microinjections of 100 mM ferric chloride. Following in vitro incubation of scar tissue with (3H) beta-Alanine, ultrastructural morphometry of grain patterns at 5, 30 and 120 days post injection revealed early and significant grain count increases (p less than 0.001) over astroglial processes, predominantly those related to perivascular glial end-feet. Astrocytic cell body and endothelial cell counts showed a more gradual and stepwise increase. Similar data were obtained by comparing visual and edited mean astrocytic grain counts. These results suggest that the enhanced uptake of reactive astrocytes may reflect a marked decrease of inhibitory GABAergic neurons within ferric chloride-induced scars.
正常哺乳动物大脑的皮质星形胶质细胞具有对β-丙氨酸的高亲和力摄取系统，该系统受到γ-氨基丁酸（GABA）的竞争性抑制，GABA是一种与癫痫发生密切相关的神经递质。我们评估了通过显微注射100 mM氯化铁在大鼠运动皮层诱导的致痫灶瘢痕内增殖的反应性星形胶质细胞对（3H）β-丙氨酸的摄取。在将瘢痕组织与（3H）β-丙氨酸进行体外孵育后，注射后5天、30天和120天对颗粒模式进行超微结构形态计量分析，结果显示星形胶质细胞突起上的颗粒计数早期即显著增加（p<0.001），主要是那些与血管周围神经胶质终足相关的突起。星形胶质细胞胞体和内皮细胞计数显示出更渐进和逐步的增加。通过比较视觉和编辑后的平均星形胶质细胞颗粒计数获得了类似的数据。这些结果表明，反应性星形胶质细胞摄取增强可能反映了氯化铁诱导的瘢痕内抑制性GABA能神经元的显著减少。
