近日,，nature雜志在線發(fā)表了瑞士和法國研究人員的研究成果,。雖然人們普遍認(rèn)為基于任務(wù)或經(jīng)驗(yàn)的學(xué)習(xí)涉及特定神經(jīng)回路內(nèi)的變化,，但我們才剛剛開始了解這些變化是怎樣發(fā)生的以及這些回路內(nèi)不同類型神經(jīng)元之間的哪些相互作用是重要的,。
研究人員以小鼠經(jīng)典的,、基于音調(diào)的恐懼條件反射作為一個(gè)模型體系,，識別出一個(gè)截然不同的、基于“去抑制”的回路,，它對于學(xué)習(xí)至關(guān)重要,。
研究人員提供的證據(jù)表明，這個(gè)回路并不是聽覺皮層特有的,，而是可能代表著“膽堿能神經(jīng)調(diào)制”門控皮層活動的一個(gè)普遍機(jī)制,。（生物谷Bioon.com）
doi:10.1038/nature10674
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A disinhibitory microcircuit for associative fear learning in the auditory cortex
Johannes J. Letzkus, Steffen B. E. Wolff, Elisabeth M. M. Meyer, Philip Tovote, Julien Courtin, Cyril Herry & Andreas Lüthi
Learning causes a change in how information is processed by neuronal circuits. Whereas synaptic plasticity, an important cellular mechanism, has been studied in great detail, we know much less about how learning is implemented at the level of neuronal circuits and, in particular, how interactions between distinct types of neurons within local networks contribute to the process of learning. Here we show that acquisition of associative fear memories depends on the recruitment of a disinhibitory microcircuit in the mouse auditory cortex. Fear-conditioning-associated disinhibition in auditory cortex is driven by foot-shock-mediated cholinergic activation of layer 1 interneurons, in turn generating inhibition of layer 2/3 parvalbumin-positive interneurons. Importantly, pharmacological or optogenetic block of pyramidal neuron disinhibition abolishes fear learning. Together, these data demonstrate that stimulus convergence in the auditory cortex is necessary for associative fear learning to complex tones, define the circuit elements mediating this convergence and suggest that layer-1-mediated disinhibition is an important mechanism underlying learning and information processing in neocortical circuits.
