非NMDA受体参与双相呼气和吸气神经元电活动的调节

Non-NMDA receptors are involved in the modulation of discharge activity of biphasic expiratory neurons and inspiratory neurons

在新生大鼠延髓脑片上同步记录舌下神经根和双相呼气神经元 /吸气神经元单位的放电活动 ,并在灌流的改良Kreb′s液中先后加以非NMDA受体的激动剂KA和拮抗剂DNQX ,观察对神经元单位放电的影响 ,以进一步探讨非NMDA受体在对双相呼气神经元之间交互兴奋和吸气神经元兴奋性突触输入中的作用。结果表明 ,使用非NMDA受体激动剂KA以后 ,双相呼气神经元的放电频率和峰频率都明显增大 ,吸气神经元中期放电的频率和峰频率也显著增大 ,而早期和晚期放电的频率无明显改变 ;用相应拮抗剂以后 ,上述效应明显被抑制。结果提示 ,非NMDA受体参与了双相呼气神经元之间的交互兴奋作用 。

Experiments were performed on in vitro brainstem slice preparations from neonatal rats that retain respiratory network activity. Extracellular recordings were made from 99 neuronal units, respiratory related or non respiratory related with rhythmical activity, out of which there were 7 biphasic expiratory and 11 inspiratory ones. Possible roles of non NMDA receptors in reciprocal excitation among the biphasic expiratory neurons and in excitatory synaptic inputs to inspiratory neurons were investigated by administration of non NMDA receptor agonist KA and its antagonist DNQX in the perfusion solution. Bath application of non NMDA receptor agonist KA increased the peak frequency of both biphasic expiratory and inspiratory neuronal discharges, and increased the discharge frequency of the biphasic expiratory neurons and the inspiratory neurons in the middle phase, while the frequency of discharge in the early and late phases were less affected. All of these effects were blocked by addition of the non NMDA receptor antagonist DNQX, suggesting the involvement of non NMDA receptors. [WT5HZ]