Preoptic mechanism for cold-defensive responses to skin cooling
Preoptic mechanism for cold-defensive responses to skin cooling
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DOI：
10.1113/jphysiol.2008.152686
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发表时间：
2008-05-15
影响因子：
5.5
通讯作者：
Morrison, Shaun F.
中科院分区：
文献类型：
--
作者：
Nakamura, Kazuhiro;Morrison, Shaun F.
我们最近发现了一种体感通路，它将温度信息从皮肤传递到视前区(POA)的中间区域，这是一个温度调节中心。在这里，我们在活体内研究了大鼠POA中处理温度感觉信息和输出温度调节效应信号的局部神经元回路。皮肤降温引起的棕色脂肪组织交感生热、代谢和心率的增加可被抑制正中视前核(MnPO)的神经元逆转。谷氨酸能刺激或解除对MnPO神经元的抑制可引起类似皮肤降温的冷防御反应的生热、代谢和心脏反应，并可通过拮抗内侧视前区(MPO)的GABA(A)受体而被逆转，该区域被认为含有向效应器提供温度调节输出的神经元。这些结果表明，由皮肤冷感觉信号激活的MnPO神经元对MPO中输出神经元的GABA抑制是POA内的一种核心体温调节机制，对于体温前馈防御环境中的冷挑战是必不可少的。
We recently identified a somatosensory pathway that transmits temperature information from the skin to a median subregion of the preoptic area (POA), a thermoregulatory centre. Here, we investigated in vivo the local neuronal circuit in the rat POA that processes the thermosensory information and outputs thermoregulatory effector signals. Skin cooling-evoked increases in sympathetic thermogenesis in brown adipose tissue, in metabolism and in heart rate were reversed by inhibition of neurons in the median preoptic nucleus (MnPO). Glutamatergic stimulation or disinhibition of MnPO neurons evoked thermogenic, metabolic and cardiac responses that mimicked the cold-defensive responses to skin cooling and were reversed by antagonizing GABA(A) receptors in the medial preoptic area (MPO), which is thought to contain neurons providing thermoregulatory output to effectors. These results suggest that GABA inhibition of output neurons in the MPO by MnPO neurons that are activated by cool sensory signals from the skin is a core thermoregulatory mechanism within the POA that is essential for the feedforward defence of body temperature against cold challenges in the environment.