Synaptic plasticity in the molluscan peripheral nervous system: physiology and role for peptides
Synaptic plasticity in the molluscan peripheral nervous system: physiology and role for peptides
复制标题
软体动物周围神经系统的突触可塑性：肽的生理学和作用
DOI：
10.1523/jneurosci.05-10-02677.1985
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发表时间：
1985
影响因子：
2.5
通讯作者：
A. Bulloch
中科院分区：
文献类型：
--
作者：
C. Coates;A. Bulloch
在各种实验，生理和药理条件下，在软体动物周围神经系统的突触可塑性进行了研究。这些研究采用了淡水蜗牛Helisoma的离体唾液腺和附着的颊神经节。在颊神经元4中诱发的动作电位通常诱发大的兴奋性突触后电位（EPSP），其驱动腺体分泌细胞中的动作电位。为了测量EPSP的调节，通过将制剂浸泡在低钙、高镁盐水中来防止腺细胞中动作电位的产生。分析了腺体EPSP幅值与4号神经元特异性生理特性的关系。与一些中央软体动物突触一样，EPSP被发现受到神经元4的膜电位的强烈影响。具体地说，其幅度降低了超极化的神经元4索马。在静息电位（-47 +/-6mV）~-100mV范围内，EPSP幅值与第4神经元体电位呈线性关系。此外，EPSP振幅与神经元4的动作电位半宽成正比。为了评估可能的生理作用，这种动作电位/EPSP的关系，我们检查是否腺体EPSP调制过程中发生的自发爆发活动和脉冲序列的尖峰展宽。在这两种条件下，上述动作电位/EPSP关系均得以维持，即，EPSP的幅度增加，作为扩大在突发或列车尖峰。还检查了神经腺传递的肽能调制。软体动物肽SCPB被发现去神经元4和EPSP振幅的增加，同时观察。（250字处删节）
The plasticity of a synapse in the molluscan peripheral nervous system was examined under a variety of experimental, physiological, and pharmacological conditions. These studies employed the isolated salivary glands and attached buccal ganglia of the freshwater snail Helisoma. Action potentials evoked in buccal neuron 4 normally evoke a large excitatory postsynaptic potential (EPSP) which drives an action potential in gland secretory cells. In order to measure modulation of the EPSP, action potential generation in gland cells was prevented by bathing the preparation in low calcium, high magnesium salines. The relationship between the gland EPSP amplitude and specific physiological properties of neuron 4 was analyzed. In common with some central molluscan synapses, the EPSP was found to be strongly influenced by the membrane potential of neuron 4. Specifically, its amplitude was reduced by hyperpolarization of the neuron 4 soma. The relationship between EPSP amplitude and somatic potential of neuron 4 was linear in the range from resting potential (-47 +/- 6mV) to -100 mV. Furthermore, the EPSP amplitude was directly proportional to the action potential half-width of neuron 4. In order to evaluate the possible physiological role of this action potential/EPSP relationship, we examined whether gland EPSPs are modulated during the spike broadening that occurs in both spontaneous burst activity and imposed impulse trains. The preceding action potential/EPSP relationship was maintained under both of these conditions, i.e., EPSP magnitude increased as spikes broadened during bursts or trains. The peptidergic modulation of neuroglandular transmission was also examined. The molluscan peptide SCPB was found to depolarize neuron 4 and an increase in EPSP amplitude was concomitantly observed.(ABSTRACT TRUNCATED AT 250 WORDS)