Short term synaptic depression imposes a frequency dependent filter on synaptic information transfer.
Short term synaptic depression imposes a frequency dependent filter on synaptic information transfer.
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DOI：
10.1371/journal.pcbi.1002557
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发表时间：
2012
影响因子：
4.3
通讯作者：
Doiron B
中科院分区：
文献类型：
--
作者：
Rosenbaum R;Rubin J;Doiron B
突触神经递质囊泡的耗尽在整个神经系统的突触中诱导一种形式的短期抑制。这种可塑性影响突触如何过滤突触前锋电位序列。短期抑郁症的过滤特性通常使用确定性突触模型来研究，该模型预测突触前尖峰序列的平均突触响应，但忽略了由囊泡释放的概率性质和突触恢复时间的随机性引入的可变性。我们表明，这种额外的可变性有重要的后果，突触前信息的突触过滤。特别是，一个突触模型与随机囊泡动力学抑制信息编码在较低的频率比信息编码在较高的频率，而忽略这种随机性的模型传输信息编码在任何频率同样好。这两个模型之间的区别仍然存在，即使当大量的突触接触被认为是。我们的研究提供了强有力的证据，随机性质的神经递质囊泡动力学必须考虑时，分析通过突触的信息流。神经元通过称为突触的电化学连接进行交流。突触前神经元中的动作电位导致神经递质囊泡释放其内容物，然后与突触后神经元膜上的附近受体结合，瞬时改变其电导。在其释放后，神经递质囊泡的替换需要时间，并且囊泡的耗尽可以防止随后的动作电位引发突触后反应，这是一种代表短期突触抑制形式的效应。当囊泡可用于释放时，动作电位以概率方式激发其释放，并且耗尽的囊泡在时间上随机地补充，使得突触前信号的传输固有地不可靠。我们分析了囊泡释放和恢复的数学模型，以了解编码在突触前动作电位序列中的信号如何反映在突触后神经元电导的波动中。我们发现，突触前动作电位速率的缓慢调制对于突触后神经元来说比更快的调制更难检测。这种现象只有在考虑囊泡释放和替换的随机性时才能观察到。因此，通过将随机性纳入突触动力学的工作中，我们对信息在神经系统中的传递方式有了新的定性理解。
Depletion of synaptic neurotransmitter vesicles induces a form of short term depression in synapses throughout the nervous system. This plasticity affects how synapses filter presynaptic spike trains. The filtering properties of short term depression are often studied using a deterministic synapse model that predicts the mean synaptic response to a presynaptic spike train, but ignores variability introduced by the probabilistic nature of vesicle release and stochasticity in synaptic recovery time. We show that this additional variability has important consequences for the synaptic filtering of presynaptic information. In particular, a synapse model with stochastic vesicle dynamics suppresses information encoded at lower frequencies more than information encoded at higher frequencies, while a model that ignores this stochasticity transfers information encoded at any frequency equally well. This distinction between the two models persists even when large numbers of synaptic contacts are considered. Our study provides strong evidence that the stochastic nature neurotransmitter vesicle dynamics must be considered when analyzing the information flow across a synapse. Neurons communicate through electro-chemical connections called synapses. Action potentials in a presynaptic neuron cause neurotransmitter vesicles to release their contents which then bind to nearby receptors on a postsynaptic neuron's membrane, transiently altering its conductance. After it is released, the replacement of a neurotransmitter vesicle takes time and the depletion of vesicles can prevent subsequent action potentials from eliciting a postsynaptic response, an effect that represents a form of short term synaptic depression. When a vesicle is available for release, an action potential elicits its release probabilistically and depleted vesicles are replenished randomly in time, making the transmission of presynaptic signals inherently unreliable. We analyze a mathematical model of vesicle release and recovery to understand how signals encoded in sequences of presynaptic action potentials are reflected in the fluctuations of a postsynaptic neuron's conductance. We find that slow modulations in the rate of presynaptic action potentials are more difficult for a postsynaptic neuron to detect than faster modulations. This phenomenon is only observed when randomness in vesicle release and replacement is taken into account. Thus, by including stochasticity in the workings of synaptic dynamics we give new qualitative understanding to how information is transferred in the nervous system.
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影响因子：
5.3
作者：
Heiss, Jaime E.;Katz, Yonatan;Lampl, Ilan
通讯作者：
Lampl, Ilan
DOI：
10.1016/s0736-5748(02)00015-1
发表时间：
2002-06-01
影响因子：
1.8
作者：
Dobrunz, LE
通讯作者：
Dobrunz, LE
影响因子：
2.9
作者：
Goldman, MS
通讯作者：
Goldman, MS
影响因子：
3.2
作者：
Loebel, Alex;Silberberg, Gilad;Richardson, Magnus J. E.
通讯作者：
Richardson, Magnus J. E.
影响因子：
56.9
作者：
KORN, H;TRILLER, A;FABER, DS
通讯作者：
FABER, DS