Astrocytes drive respiratory rhythm testing a new paradigm

吸气活动起源于一个被称为前Botzinger复合体的髓质区域(前BotC)。传统上，人们假设呼吸节律是由BotC前神经元产生的。神经胶质细胞是大脑的另一个主要细胞成分，被认为维持着神经元周围的细胞外环境，在呼吸节律的产生中扮演着不太重要的角色。在目前的研究中，我们发现星形胶质细胞(一种胶质细胞)的活动先于吸气神经元的活动。在应用河豚毒素后，呼吸神经元的输出消失，但这些星形胶质细胞保持其节律性活动。河豚毒素只抑制神经元的活动。此外，在只在星形胶质细胞上表达通道视紫红质2的转基因小鼠中，前BotC星形胶质细胞的光刺激诱导了吸气性神经元的放电。通道视紫红质2是一种离子通道，当发出光线时，它会激活细胞。这些发现表明，星形细胞蛋白Pre BotC积极参与呼吸节律的产生。

The inspiratory activity originates from a medullary region called the pre-Botzinger complex (preBotC). Traditionally, it has been hypothesized that the respiratory rhythm is generated by the preBotC neurons. Glial cells, another major cellular component of the brain, are thought to maintain extracellular environment around neurons, playing less important roles on the respiratory rhythm generation. In the present study, we discovered astrocytes (a kind of glial cell) whose activity preceded inspiratory neuronal activity. After the application of tetrodotoxin, which suppresses only neuronal activity, respiratory neuronal output disappeared, but these astrocytes maintained their rhythmic activities. In addition, in transgenic mice that expressed channelrhodopsin2 only on astrocytes, photo-stimulation of preBotC astrocytes induced firing of inspiratory neurons. Channelrhodopsin2 is an ion channel that activates the cell when a light is emitted. These findings suggest that astrocytein the preBotC are actively involved in the respiratory rhythm generation.