Loss of rhythmically bursting neurons in rat medial septum following selective lesion of septohippocampal cholinergic system
Loss of rhythmically bursting neurons in rat medial septum following selective lesion of septohippocampal cholinergic system
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DOI：
10.1152/jn.1998.79.4.1633
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发表时间：
1998-04-01
影响因子：
2.5
通讯作者：
Bassant, MH
中科院分区：
文献类型：
--
作者：
Apartis, E;Poindessous-Jazat, FR;Bassant, MH
内侧隔含有投射到海马结构的胆碱能和GABA能神经元。一个显着比例的隔海马神经元（SHN）表现出节律爆发（RB）活动，参与海马θ节律的产生。隔RE神经元的神经化学性质尚未确定。为了解决这个问题，隔单位的活动已被记录在大鼠的胆碱能隔神经元的免疫毒素192 IgG-皂草素的选择性破坏后。实验在麻醉和未麻醉的大鼠中进行，损伤后14-21天。乙酰胆碱酯酶（AChE）组织化学显示，胆碱能隔神经元和海马胆碱能纤维几乎完全丧失。记录的神经元位于Broca区内侧隔-斜角带。这些神经元中的一些被鉴定为通过对穹窿海马伞的电刺激的逆向反应投射到海马（SHN）。与对照组相比，在麻醉损伤的大鼠中，RE神经元的百分比显著降低（SHN为17 vs. 41%，未鉴定的隔神经元为5 vs. 19%）。保留RE活性的SHN的轴突传导速度和爆发频率在损伤组高于对照组。与对照组相比，损伤大鼠每次爆发的峰电位数较低，爆发持续时间较短。抗癫痫的海马theta在频率和振幅方面都发生了改变。在未麻醉的损伤大鼠，没有RE隔神经元被发现在唤醒过程中，相比之下，在对照组的25%。在异相睡眠期间，它们的数量也明显减少（9.7%对38.5%）。在192个IgG-皂草素处理的大鼠中的组织化学显示，RE神经元被发现在没有AChE阳性神经元但含有小清蛋白阳性（推测为GABA能）神经元的区域中。这些数据表明，RE活性显着降低后，选择性损伤的胆碱能内侧隔神经元。他们认为，绝大多数RE隔神经元是胆碱能的，在损伤大鼠中显示RE活性的少数神经元是GABA能的。
The medial septum contains cholinergic and GABAergic neurons that project to the hippocampal formation. A significant proportion of the septohippocampal neurons (SHN) exhibit a rhythmically bursting (RB) activity that is involved in the generation of the hippocampal theta rhythm. The neurochemical nature of septal RE neurons is not firmly established. To address this question, the septal unit activity has been recorded in rats after selective destruction of the cholinergic septal neurons by the immunotoxin 192 IgG-saporin. Experiments have been performed in urethan-anesthetized and unanesthetized rats, 14-21 days after lesion. Acetylcholinesterase (AChE) histochemistry revealed a near-complete loss of cholinergic septal neurons and of cholinergic fibers in the hippocampus. The recorded neurons were located in the medial septum-diagonal band of Broca area. A number of these neurons were identified as projecting to the hippocampus (SHN) by their antidromic response to the electrical stimulation of the fimbria-fornix. In urethan-anesthetized lesioned rats, the percentage of RE neurons decreased significantly as compared with controls (17 vs. 41% for SHNs and 5 vs. 19% for unidentified septal neurons). The axonal conduction velocity and the burst frequency of the SHNs that retained a RE activity were higher in lesioned as compared with control rats. The number of spikes per burst was lower and the burst duration was shorter in lesioned rats as compared with controls. The urethan-resistant hippocampal theta was altered both in terms of frequency and amplitude. In unanesthetized lesioned rats, no RE septal neurons were found during arousal, as compared with 25% in controls. Their number was also markedly reduced during paradoxical sleep (9.7 vs. 38.5%). Histochemistry in 192 IgG-saporin-treated rats showed that RE neurons were found in areas devoid of AChE-positive neurons but containing parvalbumine-positive (presumably GABAergic) neurons. These data show that RE activity is considerably reduced after selective lesion of the cholinergic medial septal neurons. They suggested that the large majority of the RE septal neurons are cholinergic and that the few neurons that display RE activity in lesioned rats are GABAergic.