A major role in the wake-promoting effects of the activation of the lateral hypothalamus (LH) has been ascribed to a population of orexin (ORX)-containing neurons that send projections to central areas which regulate Wake-Sleep and autonomic function. Since, in the rat, a substantial amount of ORX neurons receive cholinergic projections from cells involved in Wake-Sleep regulation, the aim of this study was to assess the role played by LH cholinoceptive cells in Wake-Sleep and autonomic regulations. To this end, the effects of a microinjection of the cholinergic agonist Carbachol (CBL) into the LH were compared to those obtained through the activation of a wider cell population by the microinjection of the GABAA antagonist GABAzine (GBZ). The results of this pilot study showed that both drugs elicited the same behavioral and autonomic effects, those caused by GBZ being larger and longer-lasting than those following administration of CBL. Briefly, wakefulness was enhanced and sleep was depressed, and brain temperature and heart rate consistently increased, while mean arterial pressure showed only a mild increment. Surprisingly, the administration of the drug vehicle (SAL) elicited a similar pattern of Wake-Sleep effects which, although much smaller, were sufficient to mask any statistical significance between treatment and control data. In conclusion, the results of this work show that the arousal elicited by LH disinhibition by GABAzine is concomitant with autonomic responses set by the intervention of cold-defense mechanisms. Since the same response is elicited at a lower level by CBL administration, the hypothesis of an involvement of cholinoceptive ORX neurons in its generation is discussed.

中文翻译：

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大鼠侧下丘脑胆碱能激活的觉醒，体温调节和自主神经作用：一项先导研究。

下丘脑外侧（LH）激活的唤醒促进作用中的主要作用归因于一群含有orexin（ORX）的神经元，这些神经元将投射物发送到调节唤醒睡眠和自主功能的中心区域。由于在大鼠中，大量的ORX神经元从参与Wake-Sleep调节的细胞接受胆碱能投射，因此本研究的目的是评估LH胆碱感受性细胞在Wake-Sleep和自主调节中的作用。为此，将通过微注射GABAA拮抗剂GABAzine（GBZ）将胆碱能激动剂卡巴胆碱（CBL）微注射到LH中的效果与通过激活更广泛的细胞群体而获得的效果进行了比较。这项初步研究的结果表明，两种药物都具有相同的行为和自主作用，由GBZ引起的症状比经CBL给药后更大，更持久。简而言之，觉醒得到增强，睡眠得到抑制，脑温和心率持续增加，而平均动脉压仅显示轻度增加。出人意料的是，施用药物媒介物（SAL）引起了类似的唤醒-睡眠效应模式，尽管其效果小得多，但足以掩盖治疗和对照数据之间的任何统计学意义。总之，这项工作的结果表明，由GABAzine抑制LH引起的唤醒与通过防寒机制的干预而引起的自主反应相伴。由于通过CBL进行较低级别的反应，因此，