BLOOD-BRAIN BARRIER OPENING TO HORSERADISH PEROXIDASE AT ONSET OF BICUCULLINE

静脉注射辣根过氧化物酶(HRP)的兔 荷包牡丹碱致小鼠全身性惊厥15分钟 为了阐明大分子穿过血液的机制- 脑屏障(BBB)在特定的神经解剖学定义的脑区。AS 通常，小动脉水平的经内皮细胞吞噬作用是 主要通道。此外，充满示踪剂的吞噬小泡 在海马体和丘脑的毛细血管中也观察到了，而 在丘脑、下丘脑和隔区，它们也存在于 小静脉内皮细胞。血管内皮细胞开口的迹象 下丘脑有紧密连接。 由于癫痫诱发的血脑屏障，HRP已经到达神经纤维层 开放，聚集在间质空间并穿透突触 裂区。囊泡形式的示踪剂进入突触前 在所有的大脑区域都观察到了可能是兴奋性的活动；它 常见于苍白球、海马体和延髓。 丘脑的强度很大。突触后树突的伴随摄取 主要出现在布通附近。与神经胶质细胞结合 这一过程非常罕见。 结论：血源性大分子通过血脑屏障通过 区域选择性、递质控制的胞饮转运和 全身性癫痫发作过程中神经元对外来蛋白的摄取 至少部分依赖于神经突触的参与 特定的大脑区域。这些研究有助于理解 癫痫发作的作用机制。

Rabbits which had received horseradish peroxidase (HRP) intravenously were subjected to bicuculline-induced generalized seizures of 15 min duration in order to elucidate the mechanism by which macromolecules traverse the blood- brain barrier (BBB) in specific neuroanatomically defined brain areas. As a rule, transendothelial pinocytosis at the level of arterioles was the main route of passage. In addition, tracer-filled pinocytotic vesicles were also observed in the capillaries of the hippocampus, thalamus, whereas in thalamus, hypothalamus and septum, they were present also in the endothelium of venules. Indication of an opening of the interendothelial tight junctions was found in the hypothalamus. The HRP, which had reached the neuropil due to the seizure-evoked BBB opening, accumulated in the interstitial spaces and penetrated the synaptic cleft region. Uptake of the tracer in vesicular form into presynaptic boutons, presumably excitatory ones, was observed in all brain regions; it was frequent in pallidum, hippocampus and medulla oblongata and very intense in the thalamus. Concomitant uptake in postsynaptic dendrites, was present mostly in the vicinity of boutons. Incorporation into glial processes was rare. It is concluded that blood-borne macromolecules traverse the BBB by regionally selective, transmitter-controlled pinocytotic transport and the the neuronal uptake of the foreign protein during the generalized seizures is at least partially dependent on the involvement of synapses of particular brain regions. These studies contribute to the understanding of mechanisms operative in epileptic seizures.