兴奋性和抑制性氨基酸对相位性呼吸神经元的影响。

Effects of excitatory and inhibitory amino acids on phasic respiratory neurons.

作者信息

Toleikis J R, Wang L, Boyarsky L L

出版信息

J Neurosci Res. 1979;4(3):225-35. doi: 10.1002/jnr.490040310.

Abstract

The responsiveness of phasically active brainstem respiratory neurons to several amino acids was investigated in cats under Dial anesthesia. Four-barreled microelectrodes were used to extrude iontophoretically the putative neurotransmitters L-glutamate, L-asparatate, glycine, and gamma-aminobutyric acid (GABA), L-glutamate and L-aspartate caused increased activity when applied to either inspiratory or expiratory neurons and appeared to be equal in efficacy. Likewise, GABA and glycine depressed ongoing phasic neural activity of both inspiratory and expiratory units. In this case, however, the dosage of GABA required to produce a given depression was significantly less than the required dosage of glycine. These findings support the hypothesis that L-glutamate and/or L-aspartate may act as excitatory neurotransmitter agents at the synapses of brainstem respiratory neurons and conversely, GABA may act as the natural inhibitory neurotransmitter.

摘要

在猫处于 Dial 麻醉状态下，研究了脑干中具有相位性活动的呼吸神经元对几种氨基酸的反应性。使用四管微电极通过离子电泳法挤出假定的神经递质 L-谷氨酸、L-天冬氨酸、甘氨酸和γ-氨基丁酸（GABA）。当将 L-谷氨酸和 L-天冬氨酸应用于吸气或呼气神经元时，会导致活动增加，并且在功效上似乎相当。同样，GABA 和甘氨酸会抑制吸气和呼气单位正在进行的相位性神经活动。然而，在这种情况下，产生给定抑制所需的 GABA 剂量明显少于所需的甘氨酸剂量。这些发现支持了这样的假设，即 L-谷氨酸和/或 L-天冬氨酸可能在脑干呼吸神经元的突触处作为兴奋性神经递质起作用，相反，GABA 可能作为天然抑制性神经递质起作用。