Wang Wengang, Richerson George B
Department of Neurology, Yale University School of Medicine, New Haven, CT 06520-8018, USA.
Respir Physiol Neurobiol. 2007 Aug 1;157(2-3):235-41. doi: 10.1016/j.resp.2007.01.012. Epub 2007 Jan 30.
A subset of serotonin neurons are putative central respiratory chemoreceptors. To test the hypothesis that serotonin neurons also have intrinsic glucose sensitivity, perforated patch recordings were made from cultured rat medullary raphé neurons after pharmacological blockade of fast glutamatergic and GABAergic synaptic transmission. It has previously been shown that all neurons stimulated by acidosis under these conditions are tryptophan hydroxylase (TPH) immunoreactive. Changes in glucose concentration from 0.1 to 20 mM had no effect on baseline firing rate of 31 neurons that were stimulated by hypercapnic acidosis. The response to hypercapnic acidosis of 25 of these neurons was the same in 0.1, 1, 2, 5 and/or 20 mM glucose as it was in 10 mM glucose. Changes in glucose also did not alter the baseline firing rate of 13 neurons that did not respond to acidosis. Although it is possible that these results were influenced by the use of tissue culture, they do not provide support for intrinsic glucose sensitivity of pH-sensitive serotonin neurons of the medullary raphé.
一部分血清素神经元被认为是中枢呼吸化学感受器。为了验证血清素神经元也具有内在葡萄糖敏感性这一假说，在对快速谷氨酸能和GABA能突触传递进行药理学阻断后，对培养的大鼠延髓中缝神经元进行了穿孔膜片钳记录。此前已有研究表明，在这些条件下，所有受酸中毒刺激的神经元均为色氨酸羟化酶（TPH）免疫反应阳性。葡萄糖浓度从0.1 mM变化到20 mM，对31个受高碳酸血症性酸中毒刺激的神经元的基础放电率没有影响。其中25个神经元在0.1 mM、1 mM、2 mM、5 mM和/或20 mM葡萄糖中的高碳酸血症性酸中毒反应与在10 mM葡萄糖中相同。葡萄糖变化也未改变13个对酸中毒无反应的神经元的基础放电率。尽管这些结果可能受到组织培养的影响，但它们并不支持延髓中缝pH敏感血清素神经元的内在葡萄糖敏感性。
