Department of OB/GYN and Reproductive Science, Yale University School of Medicine, New Haven, CT 06520, USA.
Acta Physiol (Oxf). 2010 Mar;198(3):251-62. doi: 10.1111/j.1748-1716.2009.02047.x. Epub 2009 Sep 24.
The neuropeptide hypocretin is synthesized exclusively in the lateral hypothalamus and participates in many brain functions critical for animal survival, particularly in the promotion and maintenance of arousal in animals - a core process in animal behaviours. Consistent with its arousal-promoting role in animals, the neurones synthesizing hypocretin receive extensive innervations encoding physiological, psychological and environmental cues and send final outputs to key arousal-promoting brain areas. The activity in hypocretin neurones fluctuates and correlates with the behavioural state of animals and intensive activity has been detected in hypocretin neurones during wakefulness, foraging for food and craving for addictive drugs. Therefore, it is likely that hypocretin neurones undergo experience-dependent changes resulting from intensive activations by stimuli encoding changes in the internal and external environments. This review summarizes the most recent evidence supporting experience-dependent plasticity in hypocretin neurones. Current data suggest that nutritional and behavioural factors lead to synaptic plasticity and re-organization of synaptic architecture in hypocretin neurones. This may be the substrate of enhanced levels of arousal resulting from behavioural changes in animals and may help to explain the mechanisms underlying the changes in arousal levels induced by physiological, psychological and environmental factors.
神经肽食欲素仅在外侧下丘脑合成，参与许多对动物生存至关重要的大脑功能，特别是在促进和维持动物觉醒方面 - 这是动物行为的核心过程。与食欲素在动物中促进觉醒的作用一致，合成食欲素的神经元接受广泛的传入神经，编码生理、心理和环境线索，并向关键的觉醒促进脑区发送最终输出。食欲素神经元的活动波动，并与动物的行为状态相关，在觉醒、觅食和对成瘾药物的渴望期间，已经检测到食欲素神经元的强烈活动。因此，很可能食欲素神经元经历了由编码内部和外部环境变化的刺激的强烈激活引起的经验依赖性变化。这篇综述总结了支持食欲素神经元中经验依赖性可塑性的最新证据。目前的数据表明，营养和行为因素导致食欲素神经元中的突触可塑性和突触结构的重新组织。这可能是动物行为变化导致觉醒水平增强的基础，并有助于解释生理、心理和环境因素引起的觉醒水平变化的机制。
