Factors Influencing Short-term Synaptic Plasticity in the Avian Cochlear Nucleus Magnocellularis.
Factors Influencing Short-term Synaptic Plasticity in the Avian Cochlear Nucleus Magnocellularis.
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DOI：
10.4137/jen.s25472
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发表时间：
2015
影响因子：
--
通讯作者：
Otto-Meyer S
中科院分区：
文献类型：
--
作者：
Sanchez JT;Quinones K;Otto-Meyer S
Defined as reduced neural responses during high rates of activity, synaptic depression is a form of short-term plasticity important for the temporal filtering of sound. In the avian cochlear nucleus magnocellularis (NM), an auditory brainstem structure, mechanisms regulating short-term synaptic depression include pre-, post-, and extrasynaptic factors. Using varied paired-pulse stimulus intervals, we found that the time course of synaptic depression lasts up to four seconds at late-developing NM synapses. Synaptic depression was largely reliant on exogenous Ca2+-dependent probability of presynaptic neurotransmitter release, and to a lesser extent, on the desensitization of postsynaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptor (AMPA-R). Interestingly, although extrasynaptic glutamate clearance did not play a significant role in regulating synaptic depression, blocking glutamate clearance at early-developing synapses altered synaptic dynamics, changing responses from depression to facilitation. These results suggest a developmental shift in the relative reliance on pre-, post-, and extrasynaptic factors in regulating short-term synaptic plasticity in NM.
