Richter D W, Heyde F
J Neurophysiol. 1975 Sep;38(5):1172-80. doi: 10.1152/jn.1975.38.5.1172.
In most of the bulbospinal respiratory neurons, threshold depolarization increased during the early period of their spontaneous burst discharge but decreased again at the end of a burst. In some vagal respiratory neurons, however, threshold depolarization increased steadily until the very end of their discharge period. These changes generally were accompanied by changes in the rate of depol1rization of the spikes, the amplitude of their overshoot, and their discharge frequency. For a given synaptic input, as indicated by the constancy of the interspike membrane potential trajectories, threshold depolarization of bulbospinal neurons remained constant or even decreased. Only in some vagal neurons was an increase in threshold deplarization observed under these conditions. With the exception of some vagal neurons, most of the respiratory neurons did not show a pronounced accommodative behavior when stimulated with linear rising currents. When stimulating with current pulses, all neurons discharged repetitively with only slight adaptation, which was already complete by the first few spike intervals. The current-frequency relationship was linear and revealed a primary and secondary range. The results support neither accommodation nor adaptation as important mechanisms in the genesis of the rhythmic activity of respiratory neurons.
在大多数延髓脊髓呼吸神经元中，阈去极化在其自发爆发性放电的早期增加，但在爆发结束时再次降低。然而，在一些迷走呼吸神经元中，阈去极化持续稳定增加，直到放电期结束。这些变化通常伴随着动作电位去极化速率、超射幅度及其放电频率的变化。对于给定的突触输入，如峰间膜电位轨迹的恒定性所示，延髓脊髓神经元的阈去极化保持恒定甚至降低。只有在一些迷走神经元中，在这些条件下才观察到阈去极化增加。除了一些迷走神经元外，大多数呼吸神经元在用线性上升电流刺激时没有表现出明显的适应性行为。当用电流脉冲刺激时，所有神经元都重复放电，只有轻微的适应性变化，在最初几个峰间隔时就已完成。电流-频率关系是线性的，显示出初级和次级范围。这些结果既不支持适应性也不支持适应是呼吸神经元节律性活动产生的重要机制。
