Competitive interactions between supernumerary and normal sensory neurons in the cockroach are mediated through a change in quantal content and not quantal size.
Competitive interactions between supernumerary and normal sensory neurons in the cockroach are mediated through a change in quantal content and not quantal size.
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蟑螂中多余的感觉神经元和正常的感觉神经元之间的竞争性相互作用是通过量子含量的变化而不是量子大小的变化来介导的。
DOI：
10.1152/jn.1995.74.4.1573
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发表时间：
1995
影响因子：
2.5
通讯作者：
Blagburn,JM
中科院分区：
文献类型：
--
作者：
Sosa,MA;Blagburn,JM
1.突触形成和稳定的最后步骤涉及通过接触共同目标的神经元之间的竞争性相互作用来调整连接的强度。这种竞争驱动的突触强度调整的机制还不清楚。我们已经研究了一个方面，这种现象使用一龄蟑螂尾的感觉系统。2.对在外侧丝状毛感觉神经元（L）和巨大中间神经元3（GI 3）之间的突触处记录的兴奋性突触后电位（EPSP）进行量子分析，以确定在存在额外感觉神经元（“空间侵入神经元”或SIN）的情况下观察到的EPSP振幅的降低是否是由于突触前或突触后变化。3.在SIN存在下，L-GI 3突触的平均量子含量（而非量子大小）降低。将二项式分布拟合到EPSP振幅直方图，得到可释放量子或突触位点的数量（n）和在这些位点释放的概率（p）的估计值。量子含量的减少与二项式参数n而不是p的减少有关，这表明接触、释放位点或可用于释放的量子的数量减少，而不是释放概率的变化。
1. The final steps in synapse formation and stabilization involve the adjustment of strength of connections through competitive interactions between neurons contacting a common target. The mechanisms underlying this competition-driven adjustment of synaptic strength are not well understood. We have studied one aspect of this phenomenon using the cercal sensory system of first instar cockroach nymphs. 2. Quantal analysis of excitatory postsynaptic potentials (EPSPs) recorded at the synapse between the lateral filiform hair sensory neuron (L) and giant interneuron 3 (GI3) was carried out to determine whether the reduction in EPSP amplitude observed in the presence of an additional sensory neuron ("space invader neuron" or SIN) was due to pre- or postsynaptic changes. 3. Mean quantal content, not quantal size, was reduced at the L-GI3 synapse in the presence of a SIN. Fitting binomial distributions to the EPSP amplitude histograms gave estimates of the number of releasable quanta or of synaptic sites (n) and the probability of release at these sites (p). The reduction in quantal content is associated with a decrease in the binomial parameter n and not p, suggesting that there is a decrease in the number of contacts, release sites, or quanta available for release, rather than a change in probability of release.