Respiratory rhythm generation and respiratory neuron networks

脑干呼吸网络包括多种呼吸神经元，构成呼吸中枢，产生呼吸的自动节律性和呼吸相关肌肉的时空有组织的收缩。在体内电生理和神经解剖学的研究，主要使用猫和大鼠，大大增加了我们对整个呼吸系统及其网络机制的认识。了解整个呼吸系统及其网络机制。目前，腹外侧髓质的一个有限区域，横跨称为Botzinger复合体和前Botzinger复合体的区域，是我们关注的焦点。在这一区域，已经确定了许多具有特定放电模式和特征形态特征的兴奋性和抑制性神经元。这些神经元形成的网络包括：1)吸气神经元和呼气神经元之间的抑制性连接，2)吸气神经元之间的兴奋性连接，3)抑制性连接似乎对呼吸节奏的产生至关重要，有些对形成有模式的呼吸输出至关重要。为了继续进行网络分析，我们试图通过单细胞标记和甘氨酸转运蛋白2(GLYT2) mRNA的原位杂交来确定Botzinger复合物的抑制性抑制性神经元的递质。Botzinger复合体的增加和减少呼气神经元都有GLYT2 mRNA活性，表明这些神经元使用甘氨酸作为其抑制递质。此外，我们发现位于腹侧呼吸组尾侧的其他递减呼气神经元具有GLYT2mRNA。这表明这些呼气神经元也是抑制性神经元，并使用甘氨酸。

The brainstem respiratory network, which involves a variety of respiratory neurons and constitutes the respiratory center, generates the automatic rhythmicity of respiration and the spatio-temporally organized contraction of respiration-related muscles. In vivo electrophysiological and neuroanatomical studies using largely cats and rats, have greatly increased our knowledge about the overall respiratory system and its network mechanisms. knowledge about the overall respiratory system and its network mechanisms. Currently, a limited region of the ventrolateral medulla, which spans the areas called the Botzinger complex and the pre-Botzinger complex, is the focus of our attention. In this region, a number of excitatory and inhibitory neurons with specific firing patterns and characteristic morphological features have been identified. These neurons form the networks that involve 1)inhibitory connections between inspiratory and expiratory neurons, 2)excitatory connections between inspiratory neurons, 3)inhibitory connections seem to be essential for the generation of respiratory rhythm, and some for the formation of patterned respiratory outputs. To proceed with the network analysis, we tried to determine the transmitter(s) of inhibitory inhibitory neurons of the Botzinger complex, by using single cell labeling and in situ hybridization of mRNA for glycine transporter 2(GLYT2). Both augmenting and decrementing expiratory neurons of the Botzinger complex had GLYT2 mRNA activity, suggesting that those neurons use glycine as their inhibitory transmitter. Furthermore, we found that other decrementing expiratory neurons that were located caudally in the ventral respiratory group had GLYT2mRNA. This suggested that these expiratory neurons are also inhibitory neurons and use glycine.