Respiratory Physiology & Neurobiology ( IF 2.3 ) Pub Date : 2021-07-21 , DOI: 10.1016/j.resp.2021.103744 M J Olivares 1 , A Flores 1 , R von Bernhardi 2 , J Eugenín 1
Central respiratory chemoreceptors play a key role in the respiratory homeostasis by sensing CO2 and H+ in brain and activating the respiratory neural network. This ability of specific brain regions to respond to acidosis and hypercapnia is based on neuronal and glial mechanisms. Several decades ago, glutamatergic transmission was proposed to be involved as a main mechanism in central chemoreception. However, a complete identification of mechanism has been elusive. At the rostral medulla, chemosensitive neurons of the retrotrapezoid nucleus (RTN) are glutamatergic and they are stimulated by ATP released by RTN astrocytes in response to hypercapnia. In addition, recent findings show that caudal medullary astrocytes in brainstem can also contribute as CO2 and H+ sensors that release D-serine and glutamate, both gliotransmitters able to activate the respiratory neural network. In this review, we describe the mammalian astrocytic glutamatergic contribution to the central respiratory chemoreception trying to trace in vertebrates the emergence of several components involved in this process.
中文翻译:
星形胶质细胞对脊椎动物谷氨酸相关中枢呼吸化学感受的贡献
中枢呼吸化学感受器通过感知大脑中的CO 2和H +并激活呼吸神经网络,在呼吸稳态中发挥关键作用。这种特定大脑区域对酸中毒和高碳酸血症作出反应的能力是基于神经元和神经胶质机制。几十年前,谷氨酸能传递被认为是中枢化学感受的主要机制。然而,完整的机制识别一直难以捉摸。在延髓头端,逆梯形核 (RTN) 的化学敏感神经元是谷氨酸能神经元,它们受到 RTN 星形胶质细胞响应高碳酸血症而释放的 ATP 的刺激。此外,最近的研究结果表明,脑干尾部髓质星形胶质细胞也可以作为 CO 2和 H+释放 D-丝氨酸和谷氨酸的传感器,这两种神经递质都能够激活呼吸神经网络。在这篇综述中,我们描述了哺乳动物星形细胞谷氨酸对中枢呼吸化学感受的贡献,试图在脊椎动物中追踪参与这一过程的几种成分的出现。