Center for Theoretical Biological Physics, University of California at San Diego, La Jolla, California, United States of America.
PLoS Comput Biol. 2010 Nov 4;6(11):e1000973. doi: 10.1371/journal.pcbi.1000973.
The sensitivity of a neuron to its input can be modulated in several ways. Changes in the slope of the neuronal input-output curve depend on factors such as shunting inhibition, background noise, frequency-dependent synaptic excitation, and balanced excitation and inhibition. However, in early development GABAergic interneurons are excitatory and other mechanisms such as asynchronous transmitter release might contribute to regulating neuronal sensitivity. We modeled both phasic and asynchronous synaptic transmission in early development to study the impact of activity-dependent noise and short-term plasticity on the synaptic gain. Asynchronous release decreased or increased the gain depending on the membrane conductance. In the high shunt regime, excitatory input due to asynchronous release was divisive, whereas in the low shunt regime it had a nearly multiplicative effect on the firing rate. In addition, sensitivity to correlated inputs was influenced by shunting and asynchronous release in opposite ways. Thus, asynchronous release can regulate the information flow at synapses and its impact can be flexibly modulated by the membrane conductance.
神经元对其输入的敏感性可以通过多种方式进行调节。神经元输入-输出曲线的斜率变化取决于分流抑制、背景噪声、频率依赖性突触兴奋以及平衡兴奋和抑制等因素。然而，在早期发育过程中，GABA 能中间神经元是兴奋性的，其他机制，如异步递质释放，可能有助于调节神经元的敏感性。我们模拟了早期发育过程中的相敏和异步突触传递，以研究活动依赖性噪声和短期可塑性对突触增益的影响。异步释放根据膜电导降低或增加增益。在高分流状态下，由于异步释放引起的兴奋性输入是除法的，而在低分流状态下，它对放电率几乎具有乘法效应。此外，对相关输入的敏感性受到分流和异步释放的相反影响。因此，异步释放可以调节突触的信息流，其影响可以通过膜电导灵活调节。
