Neuronal mechanisms for bilateral coordination of salivary gland activity in Helisoma.
Neuronal mechanisms for bilateral coordination of salivary gland activity in Helisoma.
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Helisoma 唾液腺活动双边协调的神经机制。
DOI：
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发表时间：
1980
期刊：
影响因子：
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通讯作者：
R. W. Joyner
中科院分区：
文献类型：
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作者：
F. Bahls;S. Kater;R. W. Joyner
Helisoma的唾液神经效应系统由成对的涎腺和颊神经节组成。以前的工作表明，两个唾液腺的活动协调需要神经元控制。这种神经元控制是由一对已识别的颊神经节神经元4R和4L提供的。本研究考察了这种神经元控制的组织结构，并讨论了单突触和多突触通路的问题以及每个神经元的双边效应4。神经元4的动作电位在唾液细胞的亚群中引发一对一的EPSP。在某些情况下，这些EPSP可以通过向神经元4注射TEA而增加，而不受添加6倍正常钙的影响。这些数据与突触传递的稳定性以及形态证据相结合，进一步表明神经元4和唾液分泌细胞之间的连接是单突触的。有三种不同的机制可以确保4R和4L的活动导致唾液腺的协调激活：(1)荧光黄注射和直接细胞内记录和刺激证明4R和4L都可以发送轴突到并神经支配两个唾液腺；(2)4R和4L都从更高阶颊神经节神经元接受几乎相同的突触输入；以及(3)4R和4L是电耦合的。因此，系统是以高度冗余的方式组织起来的，并且腺体活动的双边同步性由不同水平的神经元组织的机制来保证。
The salivary neuroeffector system of Helisoma consists of the paired salivary glands and buccal ganglia. Previous work demonstrated that neuronal control was required for coordination of activity in the two salivary glands. This neuronal control is provided by a pair of identified buccal ganglion neurons, 4R and 4L. This study examines the organization of this neuronal control and addresses the questions of monosynaptic vs. polysynaptic pathways as well as the bilateral effects of each neuron 4. Action potentials in neuron 4 elicit one-for-one EPSPs in a subpopulation of the salivary cells. These EPSPs can, in some cases, be increased by TEA injection into a neuron 4 and are unaffected by the addition of six-times normal calcium. These data coupled with the constancy of synaptic transmission, as well as morphological evidence, further indicate the monosynaptic nature of the connection between neurons 4 and salivary secretory cells. Three different mechanisms exist to insure that activity in 4R and 4L result in coordinated activation of the salivary glands: (1) Lucifer Yellow injection and direct intracellular recording and stimulation demonstrate that both 4R and 4L can send axons to and innervate both salivary glands; (2) both 4R and 4L receive virtually identical synaptic input from higher-order buccal ganglion neurons; and (3) 4R and 4L are electrically coupled. Thus, the system is organized with a high degree of redundancy, and bilateral synchrony of glandular activity is assured by mechanisms at various levels of neuronal organization.