Induction of c-fos in specific thalamic nuclei following stimulation of the pedunculopontine tegmental nucleus
Induction of c-fos in specific thalamic nuclei following stimulation of the pedunculopontine tegmental nucleus
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DOI：
10.1111/j.1460-9568.2004.03647.x
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发表时间：
2004-10-01
影响因子：
3.4
通讯作者：
Winn, P
中科院分区：
文献类型：
--
作者：
Ainge, JA;Jenkins, TA;Winn, P
桥脑脚被盖核(PPTg)是丘脑胆碱能输入的主要来源。示踪研究证实，PPTG有许多丘脑核团的投射，电生理学研究表明，乙酰胆碱(ACh)对丘脑神经元有特有的影响。行为学研究指出了PPTG在注意力中的作用，可能的一个关键底物是PPTG通过丘脑改变感觉运动门控的能力。然而，PPTg活性的改变如何影响整个丘脑的神经元活动尚不清楚。我们试图通过刺激自由活动的大鼠的PPTG并用c-fos免疫组织化学方法测量丘脑的激活来检验这一点。单侧微量注射L-谷氨酸摄取抑制剂L-反式吡咯烷-2，4-二羧酸(PDC)刺激PPTG，其原理是局部再摄取阻断增加内源性神经递质的可获得性。结果表明，PDC注入PPTg后，丘脑多个核团的Fos免疫反应均有明显而一致的改变，但以中央外侧核、腹外侧核和网状核的变化最为明显。第二项研究是为了确定PPTG内注射L-谷氨酸受体阻滞剂对大鼠行为的影响。没有观察到运动或其他一般行为的变化，这表明所观察到的丘脑Fos表达的变化不是行为输出增加的结果，而是PPTg输入增加神经元活动的直接结果。目前的数据扩展了之前的工作，通过确定哪些特定的核团受PPTg激活的影响最大，建立了桥小脑脚-丘脑的联系。
The pedunculopontine tegmental nucleus (PPTg) is a major source of cholinergic input to the thalamus. Tracing studies have established that the PPTg has projections to many thalamic nuclei and electrophysiological studies have shown acetylcholine (ACh) to have characteristic effects on thalamic neurons. Behavioural studies point to a role for the PPTg in attention and it is possible that a key substrate for this is the ability of the PPTg to modify sensorimotor gating through the thalamus. However, it is not clear how altered PPTg activity effects neuronal activity across the thalamus en masse. We have attempted to examine this by stimulating the PPTg in freely moving rats and measuring thalamic activation with c-fos immunohistochemistry. The PPTg was stimulated by unilateral microinjection of the L-glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxylic acid (PDC) with the rationale that reuptake blockade increases locally the availability of endogenous neurotransmitter. It was shown that PDC microinjection into PPTg produced clear and consistent changes in Fos immunoreactivity in several thalamic nuclei, but most markedly in the centrolateral, ventrolateral and reticular nuclei. A second study was carried out to determine the gross behavioural effects of intra-PPTg L-glutamate blockade. No changes in locomotion or other general behaviours were observed, indicating that observed changes in thalamic Fos expression were not the result of increased behavioural output but rather a direct consequence of increased neuronal activity from PPTg input. The present data extend previous work establishing pedunculopontine-thalamic connections by specifying which particular nuclei are most affected by PPTg activation.