Mechanisms underlying pattern generation in lobster stomatogastric ganglion as determined by selective inactivation of identified neurons. IV. Network properties of pyloric system.
Mechanisms underlying pattern generation in lobster stomatogastric ganglion as determined by selective inactivation of identified neurons. IV. Network properties of pyloric system.
复制标题
通过选择性失活已识别的神经元来确定龙虾口胃神经节模式生成的机制。
DOI：
10.1152/jn.1982.48.6.1416
复制
发表时间：
1982
影响因子：
2.5
通讯作者：
Selverston,AI
中科院分区：
文献类型：
--
作者：
Miller,JP;Selverston,AI
1.在本系列的前三篇论文(6、33、45)中，用染料敏化的光灭活技术研究了龙虾口胃神经节中已鉴定神经元的功能作用、内在细胞特性和突触连接。本文研究幽门系统的网络性质。2.从神经元胞体测量所有可能的运动神经元对之间突触相互作用的相对强度。3.实验确定了幽门神经元中仅因网络相互作用而产生节律性活动的最小亚群。排除了内源性爆裂的前爆裂(AB)细胞，发现最小数量的元素是两个。当这两个元素的总体活动水平被适当调整时，它们的行为就像一个经典的“半中心”振荡器。4.连合神经节中的两个细胞为幽门系统提供节律性兴奋性输入相，锁定在幽门持续活动中。输入的节奏性在功能上是不相关的。这些输入可以通过紧张性放电对幽门系统的活动产生影响。5.根据幽门神经元的固有特性及其形成的网络的系统特性，定性地解释了幽门运动模式的三个重要方面。这种模式的存在是单个神经元的振荡膜属性与网络中多个相互抑制的相互作用相结合的结果。这些时相关系源于突触连接，依赖于相对突触强度、抑制后反弹、反弹延迟以及平台和爆发性起搏电位产生机制的动力学。整个模式的频率是由AB中间神经元通过其固有的振荡行为和与其余幽门神经元的强突触决定的。
1. In three preceding papers in this series (6, 33, 45), the functional roles, intrinsic cellular properties, and synaptic connections of identified neurons in the lobster stomatogastric ganglion were investigated using the dye-sensitized photoinactivation technique. In this paper, we investigate the network properties of the pyloric system. 2. The relative strengths of the synaptic interactions between all possible motor neuron pairs were measured from the neuronal cell bodies. 3. Experiments were performed to determine the minimal subset of the pyloric neurons that could generate rhythmic activity due to network interactions alone. With the endogenously bursting anterior burster (AB) cell excluded from consideration, the minimum number of elements was found to be two. These two elements behaved as a classical "half-center" oscillator when their overall activity levels were appropriately adjusted. 4. Two cells in the commissural ganglia supply the pyloric system with rhythmic excitatory input phase locked to ongoing pyloric activity. The rhythmicity of that input is shown to be functionally irrelevant. The inputs can exert their effects on pyloric system activity through tonic firing. 5. A qualitative explanation of three important aspects of the pyloric motor pattern is presented, based on the intrinsic properties of pyloric neurons and the systematic properties of the network they form. The existence of the pattern results from oscillatory membrane properties of the individual neurons in combination with the multiple reciprocally inhibitory interactions within the network. The phase relationships derive from the synaptic connectivity and depend on relative synaptic strengths, postinhibitory rebound, rebound delay, and the kinetics of the plateau and bursting pacemaker-potential generation mechanisms. The overall pattern frequency is determined by the AB interneuron via its intrinsic oscillatory behavior and strong synapses with the rest of the pyloric neurons.