AFFERENT MODULATION OF RESPIRATORY PATTERN IN VITRO

将使用分离的新生大鼠脑干/脊髓制备物 研究神经群体之间的相互作用， 产生呼吸节律和传入输入，重置这一点 节奏在该制备中，产生呼吸节律的网络是 功能齐全，它们的细胞和突触特性很容易 容易接近内源性爆发细胞（其膜电位 在没有突触输入的情况下振荡）已经在这一研究中被确定。 准备.在某些呼吸节律发生模型中，内源性 爆发器通过其爆发频率确定呼吸频率， 已知其是它们的静息膜电位的函数。 初步研究表明，呼吸节律是由电重置 刺激迷走神经。的影响 刺激是呼吸周期中何时发生的函数： 当在吸气期间施加刺激时吸气缩短， 当刺激在早期应用时， 当刺激施加到晚期时， 过期如果内源性爆发决定呼吸频率，那么 刺激诱导的呼吸节律重置必须集中于这些 细胞在刺激诱导的重置过程中监测内源性爆发 将检验这一假设，并区分 呼吸功能回路的替代模型之间 节律发生 表征了介导细胞和突触机制， 中枢产生的节律和传入反馈的相互作用可能会 光的神经基础上的呼吸道病变，产生了 中枢产生的节奏和感觉的不适当的耦合 反馈在这种制备中，这种病理的神经基础可以 进行研究，并开发新的治疗干预措施。

The isolated neonate rat brainstem/spinal cord preparation will be used to investigate the interaction between neural populations mediating the generation of respiratory rhythm and afferent inputs that reset this rhythm. In this preparation, networks generating respiratory rhythm are fully functional, and their cellular and synaptic properties are readily accessible. Endogenous bursters (cells whose membrane potentials oscillate in the absence of synaptic input) have been identified in this preparation. In some models of respiratory rhythmogenesis, endogenous bursters determine respiratory frequency by their bursting frequency, which is known to be a function of their resting membrane potentials. Preliminary studies show that respiratory rhythm is reset by electrical stimulation to the vagus nerve in this preparation. The effect of stimulation is a function of when it occurs in the respiratory cycle: inspiration is shortened when the stimulus is applied during inspiration, expiration is lengthened when the stimulus is applied early in expiration, and shortened when the stimulus is applied late in expiration. If endogenous bursters determine respiratory frequency, then stimulus-induced resetting of respiratory rhythm must converge on these cells. Monitoring endogenous bursters during stimulus-induced resetting of respiratory rhythm will test this hypothesis, and differentiate between alternative models of the functional circuitry for respiratory rhythmogenesis. Characterizing the cellular and synaptic mechanisms mediating the interaction of centrally generated rhythm and afferent feedback may shed light on the neural basis of respiratory pathologies which arise out of the inappropriate coupling of centrally generated rhythm and sensory feedback. In this preparation the neural basis for such pathologies can be investigated, and novel therapeutic interventions developed.