Hars B, Maho C, Edeline J M, Hennevin E
Laboratoire de Neurobiologie de l'Apprentissage et de la Mémoire, URA 1491, CNRS, Université Paris-Sud, Orsay, France.
Neuroscience. 1993 Sep;56(1):61-74. doi: 10.1016/0306-4522(93)90562-t.
The effects of unilateral basal forebrain stimulation on the tone-evoked responses recorded in the auditory cortex ipsilateral and contralateral to the stimulation site, were investigated in fully awake rats. After 10 tone alone presentations, 20 pairing trials were given during which the basal forebrain stimulation was followed by the tone 30 ms later. Ten test-tones were presented immediately, 15 min and 1 h after pairing. Immediately after pairing, the short-latency "on" and "off" tone-evoked responses were enhanced in the ipsilateral but not in the contralateral cortex. This enhancement did not persist 15 min later. Systemic atropine injection prevented the ipsilateral facilitation. The responses to the tone were not modified when tested after 20 basal forebrain stimulations delivered in the absence of the tone. These results are the first demonstration in awake animals that an activation of the auditory cortex by cholinergic neurons of the basal forebrain is able to facilitate cortical responsiveness. A temporal contiguity between the cholinergic activation and the neuronal discharges elicited by the sensory stimulus is required for the facilitation to take place. The results are compared to previous ones obtained in anesthetized animals, and the functional role of cholinergic activation from the basal forebrain in cortical processing is discussed.
在完全清醒的大鼠中，研究了单侧基底前脑刺激对在刺激部位同侧和对侧听觉皮层记录的纯音诱发反应的影响。在单独呈现10次纯音后，进行20次配对试验，在此期间，基底前脑刺激后30毫秒再呈现纯音。在配对后立即、15分钟和1小时分别呈现10次测试纯音。配对后立即，同侧皮层中短潜伏期的“开”和“关”纯音诱发反应增强，而对侧皮层中未增强。这种增强在15分钟后未持续。全身注射阿托品可阻止同侧的易化作用。在无纯音情况下进行20次基底前脑刺激后进行测试时，对纯音的反应未改变。这些结果首次在清醒动物中证明，基底前脑胆碱能神经元对听觉皮层的激活能够促进皮层反应性。促进作用发生需要胆碱能激活与感觉刺激引发的神经元放电之间存在时间上的连续性。将这些结果与之前在麻醉动物中获得的结果进行了比较，并讨论了基底前脑胆碱能激活在皮层处理中的功能作用。
