Department of Zoology and Bodega Marine Laboratory, University of California, Berkeley, California 94720.
J Gen Physiol. 1973 Oct 1;62(4):448-72. doi: 10.1085/jgp.62.4.448.
External recording and stimulation, techniques were used to determine which neurons and interactions are essential for production of the periodic burst discharge in the lobster cardiac ganglion. Burst activity can be modulated by brief single shocks applied to the four small cells, but not by similar stimulation of the five large cells, suggesting that normally one or more small cells primarily determine burst rate and duration. Repetitive electrical stimulation of large cells initiates spike activity in small cells, probably via excitatory synaptic and/or electrotonic connections which may normally act to prolong bursts and decrease burst rate. Transection of the ganglion can result in burst activity in small cells in the partial or complete absence of large cell spike activity, but large cells isolated from small cell excitatory synaptic input by transection or by application of dinitrophenol do not burst. Generally, transections which decrease excitatory feedback to small cells are accompanied by an increase in burst rate, but mean spike frequency over an entire burst cycle stabilizes at the original level within 10-30 min for various groups of cells whose spike-initiating sites are still intact. These and previous results suggest that the system is two layered: one or more small cells generate the burst pattern and impose it on the large cells which are the system's motorneurons.
采用外部记录和刺激技术，以确定哪些神经元和相互作用对于龙虾心神经节中周期性爆发放电的产生是必要的。爆发活动可以通过施加于四个小细胞的短暂单次刺激来调制，但不能通过类似地刺激五个大细胞来调制，这表明通常一个或多个小细胞主要决定爆发率和持续时间。大细胞的重复电刺激引发小细胞的尖峰活动，可能通过兴奋性突触和/或电紧张连接，这些连接通常作用于延长爆发并降低爆发率。神经节的横切可导致小细胞中的爆发活动，即使在大细胞尖峰活动的部分或完全缺失的情况下，但是通过横切或应用二硝基苯酚从小细胞兴奋性突触输入分离的大细胞不爆发。通常，减少向小细胞的兴奋性反馈的横切伴随着爆发率的增加，但对于其起始位点仍完整的各种细胞组，整个爆发周期的平均尖峰频率在 10-30 分钟内稳定在原始水平。这些和以前的结果表明该系统是两层的：一个或多个小细胞产生爆发模式，并将其强加于大细胞，大细胞是系统的运动神经元。
