The central piriform cortex:: Anatomical connections and anticonvulsant effect of GABA elevation in the kindling model
The central piriform cortex:: Anatomical connections and anticonvulsant effect of GABA elevation in the kindling model
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DOI：
10.1016/j.neuroscience.2004.04.022
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发表时间：
2004-01-01
期刊：
影响因子：
3.3
通讯作者：
Löscher, W
中科院分区：
文献类型：
--
作者：
Schwabe, K;Ebert, U;Löscher, W
梨状皮质（PC）被认为是在大鼠前脑（边缘型）癫痫发作的产生和传播的关键参与。PC在大鼠脑腹外侧的大面积上延伸，前部对荷包牡丹碱诱导的癫痫高度敏感，中部对电诱导的癫痫最敏感。因此，PC的不同部分可能与癫痫发作活动的产生和传播有关。由于以前的研究表明，在PC中的GABA能抑制的损失涉及癫痫活动的产生，我们在先前杏仁核点燃大鼠的前，中央和后PC双侧微量注射GABA-转氨酶阻断剂氨己烯酸，并反复测试其对点燃癫痫发作的影响。氨己烯酸在所有组中均具有抗惊厥作用，持续时间长达13天，注射后24 h具有最大效应。然而，在中央PC中微量注射后，对癫痫发作泛化的抗惊厥作用最强，这表明在这一部分中的GABA能突触与全身性癫痫发作的发展密切相关。由于PC区域的解剖连接的差异可能是癫痫发作易感性的差异，我们解决了这个问题，通过注射顺行示踪剂菜豆白细胞凝集素在不同的PC亚区。虽然有相似之处，从不同的PC亚区的预测，我们也发现PC亚区之间的差异，在其预测的结构，已知是重要的边缘癫痫发作网络，如嗅周皮质，核丘脑和纹状体。PC亚区之间的解剖连接的这些差异可能涉及在本研究和以前的研究中观察到的癫痫发作易感性的差异。(C)2004年IBRO。由爱思唯尔有限公司出版。保留所有权利。
The piriform cortex (PC) is thought to be critically involved in the generation and propagation of forebrain (limbic type) seizures in the rat. The PC extends over a large area at the ventrolateral side of the rat brain with an anterior part highly sensitive for bicuculline-induced and a central part most sensitive for electrically induced seizures. Therefore, distinct parts of the PC might be differentially involved in the generation and spread of seizure activity. Since previous studies indicated that a loss of GABAergic inhibition in the PC is involved in the generation of epileptic activity, we microinjected the GABA-transaminase blocker vigabatrin bilaterally in the anterior, central and posterior PC of previously amygdala-kindled rats and repeatedly tested its effect on kindled seizures. Vigabatrin was anticonvulsant in all groups for up to 13 days with a maximal effect 24 h after injection. However, the anticonvulsant effect on seizure generalization was strongest after microinjection in the central PC suggesting that GABAergic synapses in this part are critically involved in the development of generalized seizures. Since differences in anatomical connections of the PC regions may be responsible for differences in seizure susceptibility, we addressed this question by injection of the anterograde tracer Phaseolus vulgaris leucoagglutinin in different PC subregions. Although there were similarities in the projections from different PC subregions, we also found differences between the PC subregions in their projections to structures known to be important in the limbic seizure network, such as the perirhinal cortex, nucleus accumbens, and striatum. These differences in anatomical connectivity between PC subregions may be involved in the differences in seizure susceptibility observed in the present and previous studies. (C) 2004 IBRO. Published by Elsevier Ltd. All rights reserved.