Central efferent pathways mediating skin cooling-evoked sympathetic thermogenesis in brown adipose tissue
Central efferent pathways mediating skin cooling-evoked sympathetic thermogenesis in brown adipose tissue
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DOI：
10.1152/ajpregu.00427.2006
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发表时间：
2007-01-01
影响因子：
2.8
通讯作者：
Morrison, Shaun F.
中科院分区：
文献类型：
--
作者：
Nakamura, Kazuhiro;Morrison, Shaun F.
自主神经系统对热调节效应的控制是快速冷防御反应的关键组成部分，这是由皮肤的热信息触发的。然而，驱动热调节效应对皮肤热信号反应的中枢自主机制仍有待确定。在这里，我们通过监测产热[BAT交感神经活动（SNA）和BAT温度]、代谢（呼气二氧化碳）和心血管（动脉压和心率）参数，研究了尿素氯氯醛麻醉大鼠棕色脂肪组织（BAT）对皮肤冷却的交感热反应中几个自主脑区域的参与。急性皮肤降温，既没有降低直肠（核心）温度，也没有降低脑温度，却诱发了BAT SNA、BAT温度、过期二氧化碳和心率的增加。双侧微注射双丘碱（GABA(A)受体拮抗剂）到视前区（POA），双侧微注射muscimol （GABAA受体激动剂）到下丘脑背内侧核（DMH），或微注射muscimol、甘氨酸、8-羟基- dpat （5-HT1A受体激动剂），可以抑制皮肤冷却引起的生热、代谢和心率反应。或kynurenate（嗜离子性兴奋性氨基酸受体的非选择性拮抗剂）进入吻侧白斑中段核（rRPa），但不能通过双侧肌肉注射进入尾侧导水管周围灰质的外侧/背外侧或腹外侧。这些结果表明，POA、DMH和rRPa在皮肤冷却的产热、代谢和心脏反应的中枢传出通路中，并表明这些通路可以通过向髓系神经输入5 -羟色胺能来调节。
Control of thermoregulatory effectors by the autonomic nervous system is a critical component of rapid cold-defense responses, which are triggered by thermal information from the skin. However, the central autonomic mechanism driving thermoregulatory effector responses to skin thermal signals remains to be determined. Here, we examined the involvement of several autonomic brain regions in sympathetic thermogenic responses in brown adipose tissue (BAT) to skin cooling in urethanechloralose-anesthetized rats by monitoring thermogenic [BAT sympathetic nerve activity (SNA) and BAT temperature], metabolic (expired CO2), and cardiovascular (arterial pressure and heart rate) parameters. Acute skin cooling, which did not reduce either rectal (core) or brain temperature, evoked increases in BAT SNA, BAT temperature, expired CO2, and heart rate. Skin cooling-evoked thermogenic, metabolic, and heart rate responses were inhibited by bilateral microinjections of bicuculline (GABA(A) receptor antagonist) into the preoptic area (POA), by bilateral microinjections of muscimol (GABAA receptor agonist) into the dorsomedial hypothalamic nucleus (DMH), or by microinjection of muscimol, glycine, 8-OH-DPAT (5-HT1A receptor agonist), or kynurenate (nonselective antagonist for ionotropic excitatory amino acid receptors) into the rostral raphe pallidus nucleus (rRPa) but not by bilateral muscimol injections into the lateral/dorsolateral part or ventrolateral part of the caudal periaqueductal gray. These results implicate the POA, DMH, and rRPa in the central efferent pathways for thermogenic, metabolic, and cardiac responses to skin cooling, and suggest that these pathways can be modulated by serotonergic inputs to the medullary raphe.