Hebbian and Homeostatic Plasticity Mechanisms in Regular Spiking and Intrinsic Bursting Cells of Cortical Layer 5.
Hebbian and Homeostatic Plasticity Mechanisms in Regular Spiking and Intrinsic Bursting Cells of Cortical Layer 5.
复制标题
DOI：
10.1016/j.neuron.2015.09.025
复制
发表时间：
2015-11-04
期刊：
影响因子：
16.2
通讯作者：
Fox K
中科院分区：
文献类型：
--
作者：
Greenhill SD;Ranson A;Fox K
第5层包含新皮质的主要投射神经元，由两种主要细胞类型组成：具有皮质-皮质投射的规则尖峰（RS）细胞和具有皮质下投射的内在爆发细胞（IB）。很少有人知道的可塑性过程，特别是这两个细胞类的发展和保持其独特的综合性能的分子机制。在这项研究中，我们发现，RS和IB细胞表现出根本不同的经验依赖的可塑性过程，并整合赫布和稳态成分的可塑性不同。RS和IB细胞在感觉剥夺时均表现出TNFα依赖的稳态可塑性，但IB细胞比RS细胞更快的突触抑制和稳态反弹。只有IB细胞表现出依赖于CaMKII自身磷酸化的输入特异性增强。我们的研究结果表明，可塑性机制是不统一的新皮层，甚至在皮层层，但专门的子电路。RS和IB细胞表现出依赖于TNFα的自抑郁的稳态恢复IB细胞表现出依赖于CaMKII的输入特异性增强，但RS细胞不表现出依赖于TNFα的稳态可塑性，其持续至成年期的皮质层5中RS和IB细胞的mEPSC反映了其感觉诱发的尖峰放电率的变化。显示小鼠桶状皮层中的第5层细胞亚型（规则尖峰和内在爆发）显示出不同形式的可塑性，这些可塑性依赖于不同的分子机制来响应感觉剥夺。
Layer 5 contains the major projection neurons of the neocortex and is composed of two major cell types: regular spiking (RS) cells, which have cortico-cortical projections, and intrinsic bursting cells (IB), which have subcortical projections. Little is known about the plasticity processes and specifically the molecular mechanisms by which these two cell classes develop and maintain their unique integrative properties. In this study, we find that RS and IB cells show fundementally different experience-dependent plasticity processes and integrate Hebbian and homeostatic components of plasticity differently. Both RS and IB cells showed TNFα-dependent homeostatic plasticity in response to sensory deprivation, but IB cells were capable of a much faster synaptic depression and homeostatic rebound than RS cells. Only IB cells showed input-specific potentiation that depended on CaMKII autophosphorylation. Our findings demonstrate that plasticity mechanisms are not uniform within the neocortex, even within a cortical layer, but are specialized within subcircuits. RS and IB cells exhibit TNFα-dependent homeostatic recovery from depression IB cells exhibit CaMKII-dependent, input-specific potentiation, but RS cells do not TNFα-dependent homeostatic plasticity persists into adulthood in cortical layer 5 mEPSCs of RS and IB cells mirror changes in their sensory evoked spike firing rates Using in vivo electrophysiology, Greenhill et al. show that layer 5 cell subtypes (regular spiking and intrinsic bursting) in the mouse barrel cortex show differing forms of plasticity that rely on different molecular mechanisms in response to sensory deprivation.