A SWITCH BETWEEN 2 MODES OF SYNAPTIC TRANSMISSION MEDIATED BY PRESYNAPTIC INHIBITION
A SWITCH BETWEEN 2 MODES OF SYNAPTIC TRANSMISSION MEDIATED BY PRESYNAPTIC INHIBITION
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DOI：
10.1038/378502a0
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发表时间：
1995-11-30
期刊：
影响因子：
64.8
通讯作者：
NUSBAUM, MP
中科院分区：
文献类型：
--
作者：
COLEMAN, MJ;MEYRAND, P;NUSBAUM, MP
突触前抑制减少了中枢神经系统中神经元对之间的化学突触传递（1-4），但其在形成神经网络活动基础上的多突触相互作用中的作用尚未得到很好的研究。因此，我们利用甲壳类动物口胃神经系统来研究突触前抑制已识别的投射神经元，调节性联合神经元1 (MCN1)，如何影响MCN1对胃磨神经网络的突触效应。补性MCN1放电刺激胃磨网神经元并激活胃磨节律（5,6）。一个网络神经元，侧胃（LG）神经元，突触前抑制MCN1并电偶联到其末端（5,6）。我们在这里表明，这种突触前抑制选择性地减少或消除MCN1的递质介导的兴奋，而不减少其电介导的兴奋作用，从而切换由MCN1兴奋的网络神经元。通过改变MCN1的突触输出类型，从而改变激活的网络神经元，这种突触前抑制对运动模式的产生至关重要。
PRESYNAPTIC inhibition reduces chemical synaptic transmission in the central nervous system between pairs of neurons(1-4), but its role(s) in shaping the multisynaptic interactions underlying neural network activity are not well studied. We therefore used the crustacean stomatogastric nervous system to study how presynaptic inhibition of the identified projection neuron, modulatory commissural neuron 1 (MCN1), influences the MCN1 synaptic effects on the gastric mill neural network. Tonic MCN1 discharge excites gastric mill network neurons and activates the gastric mill rhythm(5,6). One network neuron, the lateral gastric (LG) neuron, presynaptically inhibits MCN1 and is electrically coupled to its terminals(5,6). We show here that this presynaptic inhibition selectively reduces or eliminates transmitter-mediated excitation from MCN1 without reducing its electrically mediated excitatory effects, thereby switching the network neurons excited by MCN1. By switching the type of synaptic output from MCN1 and, hence, the activated network neurons, this presynaptic inhibition is pivotal to motor pattern generation.