School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK.
Front Neuroendocrinol. 2015 Apr;37:97-107. doi: 10.1016/j.yfrne.2014.10.003. Epub 2014 Oct 29.
Seasonal cycles of fattening and body weight reflecting changes in both food intake and energy expenditure are a core aspect of the biology of mammals that have evolved in temperate and arctic latitudes. Identifying the neuroendocrine mechanisms that underlie these cycles has provided new insights into the hypothalamic control of appetite and fuel oxidation. Surprisingly, seasonal cycles do not result from changes in the leptin-responsive and homeostatic pathways located in the mediobasal and lateral hypothalamus that regulate meal timing and compensatory responses to starvation or caloric restriction. Rather, they result from changes in tanycyte function, which locally regulates transport and metabolism of thyroid hormone and retinoic acid. These signals are crucial for the initial development of the brain, so it is hypothesized that seasonal neuroendocrine cycles reflect developmental mechanisms in the adult hypothalamus, manifest as changes in neurogenesis and plasticity of connections.
季节性的育肥和体重变化反映了食物摄入和能量消耗的变化，这是在温带和北极地区进化的哺乳动物生物学的核心方面。确定这些周期的神经内分泌机制为下丘脑对食欲和燃料氧化的控制提供了新的见解。令人惊讶的是，季节性周期不是由于位于中脑基底和外侧下丘脑的瘦素反应和稳态途径的变化引起的，这些途径调节进餐时间和对饥饿或热量限制的补偿反应。相反，它们是由于 tanycyte 功能的变化引起的，tanycyte 功能局部调节甲状腺激素和视黄酸的运输和代谢。这些信号对于大脑的最初发育至关重要，因此假设季节性神经内分泌周期反映了成年下丘脑的发育机制，表现为神经发生和连接可塑性的变化。
