Intrinsic membrane properties of pre-oromotor neurons in the intermediate zone of the medullary reticular formation.
Intrinsic membrane properties of pre-oromotor neurons in the intermediate zone of the medullary reticular formation.
复制标题
髓质网状结构中间区前口腔运动神经元的内在膜特性。
DOI：
10.1016/j.neuroscience.2010.03.036
复制
发表时间：
2010
期刊：
影响因子：
3.3
通讯作者：
Travers,JB
中科院分区：
文献类型：
--
作者：
Venugopal,S;Boulant,JA;Chen,Z;Travers,JB
控制完成行为的下脑干神经元广泛分布在脑桥和延髓的网状结构（RF）中。在这个分布式系统内的神经元的固有膜特性形状复杂的兴奋性和抑制性输入从orosensory和中央结构牵连在稳态控制，以产生协调orosensory模式。本研究探讨了延髓网状结构（IRt）中间亚部神经元的内在膜特性。IRt的神经元接受来自孤束的上覆（味觉）核的输入，并投射到orbital核。最近的行为药理学研究以及计算模型表明，抑制在IRt中起着重要的作用，从一个味道启动orbestic模式的摄入，拒绝之一的过渡。本研究探讨了超极化对膜性质的影响。在响应于去极化，神经元响应于强直性放电，不规则/突发模式或尖峰适应。一个超极化的前脉冲调制大多数（82%）IRt神经元的兴奋性随后去极化。观察到兴奋性增加（30%）和降低（52%）的两种情况。由超极化引起的电流包括抑制兴奋性的外向4-氨基吡啶（4-AP）敏感的K+电流和增加兴奋性的内向阳离子电流。这些电流也存在于RF神经元的其他亚群，影响orthodonucleus，我们讨论这些电流如何改变发射特性，影响图案的生成。
Neurons in the lower brainstem that control consummatory behavior are widely distributed in the reticular formation (RF) of the pons and medulla. The intrinsic membrane properties of neurons within this distributed system shape complex excitatory and inhibitory inputs from both orosensory and central structures implicated in homeostatic control to produce coordinated oromotor patterns. The current study explored the intrinsic membrane properties of neurons in the intermediate subdivision of the medullary reticular formation (IRt). Neurons in the IRt receive input from the overlying (gustatory) nucleus of the solitary tract and project to the oromotor nuclei. Recent behavioral pharmacology studies as well as computational modeling suggest that inhibition in the IRt plays an important role in the transition from a taste-initiated oromotor pattern of ingestion to one of rejection. The present study explored the impact of hyperpolarization on membrane properties. In response to depolarization, neurons responded with either a tonic discharge, an irregular/burst pattern or were spike-adaptive. A hyperpolarizing pre-pulse modulated the excitability of most (82%) IRt neurons to subsequent depolarization. Instances of both increased (30%) and decreased (52%) excitability were observed. Currents induced by the hyperpolarization included an outward 4-aminopyridine (4-AP) sensitive K+current that suppressed excitability and an inward cation current that increased excitability. These currents are also present in other subpopulations of RF neurons that influence the oromotor nuclei and we discuss how these currents could alter firing characteristics to impact pattern generation.