Mechanisms of bi-directional modulation of thalamocortical transmission in barrel cortex by presynaptic kainate receptors
Mechanisms of bi-directional modulation of thalamocortical transmission in barrel cortex by presynaptic kainate receptors
复制标题
DOI：
10.1016/j.neuropharm.2010.12.023
复制
发表时间：
2011-05-01
影响因子：
4.7
通讯作者：
Isaac, John T. R.
中科院分区：
文献类型：
--
作者：
Jouhanneau, Jean-Sebastien;Ball, Simon M.;Isaac, John T. R.
突触前红藻氨酸受体在突触传递和短时程可塑性中发挥重要作用，深刻调节哺乳动物大脑许多部位的网络活动。在初级感觉新皮层中，短期突触可塑性对于感受野结构和信息处理是重要的，红藻氨酸受体高度表达并调节丘脑皮质输入，特别是在发育期间。然而，红藻氨酸受体依赖的突触前调节丘脑皮层传递的机制尚不清楚。因此，我们研究了这个问题，结合药理学和生化分析，在新生儿丘脑皮层切片桶皮质电生理。我们发现，突触前红藻氨酸受体可以促进或抑制突触传递取决于其激活的程度。这种双向调节部分由红藻氨酸受体介导，红藻氨酸受体直接影响丘脑皮质轴突兴奋性，但也可能涉及作用于丘脑皮质末端的受体以调节递质释放。红藻氨酸盐在调节丘脑皮层传输的功效是低的相比，报告的其他输入。与这种低疗效一致，我们的生化分析表明，突触前红藻氨酸受体调节新生儿丘脑皮质输入可能缺乏高红藻氨酸亲和力GluK4和5亚基。因此，低亲和力红藻氨酸受体可通过两种机制双向调节丘脑皮质传递。这种突触前调节提供了一个潜在的强大的机制，影响桶皮层发育过程中的感觉处理。(C)2010年由Elsevier Ltd.出版
Presynaptic kainate receptors play an important role in synaptic transmission and short-term plasticity to profoundly regulate network activity in many parts of the mammalian brain. In primary sensory neocortex, where short-term synaptic plasticity is important for receptive field structure and information processing, kainate receptors are highly expressed and regulate thalamocortical inputs, particularly during development. However, the mechanisms of the kainate receptor-dependent presynaptic regulation of thalamocortical transmission are unclear. We therefore investigated this issue using electrophysiology in neonatal thalamocortical slices of barrel cortex combined with pharmacology and biochemical analyses. We show that presynaptic kainate receptors can both facilitate or depress synaptic transmission depending on the extent of their activation. This bi-directional regulation is mediated in part by kainate receptors that directly influence thalamocortical axonal excitability, but also likely involves receptors acting at thalamocortical terminals to regulate transmitter release. The efficacy of kainate in regulating thalamocortical transmission is low compared to that reported for other inputs. Consistent with this low efficacy, our biochemical analyses indicate that the presynaptic kainate receptors regulating neonatal thalamocortical inputs likely lack the high kainate affinity GluK4 and 5 subunits. Thus thalamocortical transmission can be bi-directionally regulated by low affinity kainate receptors through two mechanisms. Such presynaptic regulation provides a potentially powerful mechanism to influence sensory processing during development of barrel cortex. (C) 2010 Published by Elsevier Ltd.