Pyramidal cell communication within local networks in layer 2/3 of rat neocortex
Pyramidal cell communication within local networks in layer 2/3 of rat neocortex
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DOI：
10.1113/jphysiol.2003.044784
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发表时间：
2003-08-15
影响因子：
5.5
通讯作者：
Zilberter, Y
中科院分区：
文献类型：
--
作者：
Holmgren, C;Harkany, T;Zilberter, Y
新皮层锥体细胞作为局部网络发挥作用的程度取决于它们之间连接的强度和概率。通过映射锥体细胞之间的连接，我们在这里表明，在一个本地网络的约600锥体细胞位于一个圆柱形体积的200妈妈× 200妈妈的新皮层层2/3，一个单独的锥体细胞接收突触输入约30个其他锥体神经元，与大多数的EPSP幅度在0.2-1.0 mV的范围。连接的概率从0.09下降到0.01与细胞间的距离（在范围25-200妈妈）。在相同体积内，局部中间神经元（快速尖峰非适应性中间神经元，FS）-锥体细胞连接的数量约为10倍，大多数连接是相互的。锥体细胞和FS中间神经元之间的兴奋性和抑制性连接的概率仅随距离略有下降，在0.5-0.75的范围内。在局部网络中的锥体细胞在层1和层6中的传入纤维的刺激期间接收到强突触输入。最小的刺激层1或层6的输入同时诱导突触后电位在连接的锥体细胞，以及在海马-FS细胞对。这些输入很容易引起发射的锥体细胞，虽然突触连接的细胞显示不同的放电模式。单一的EPSPs在锥体细胞对没有检测到改变细胞放电。FS中间神经元与锥体细胞同时放电。在单细胞-FS细胞对中，单一EPSP和IPSP都有效地调制细胞放电模式。我们认为，在本地网络中的计算不仅可以进行直接的锥体细胞通信，但也通过本地interneurons。由于与周围锥体细胞的连接程度如此之高，局部中间神经元理想地准备通过锥体-中间神经元-锥体通信来协调和扩展局部锥体细胞网络。
The extent to which neocortical pyramidal cells function as a local network is determined by the strength and probability of their connections. By mapping connections between pyramidal cells we show here that in a local network of about 600 pyramidal cells located within a cylindrical volume of 200 mum x 200 mum of neocortical layer 2/3, an individual pyramidal cell receives synaptic inputs from about 30 other pyramidal neurons, with the majority of EPSP amplitudes in the 0.2-1.0 mV range. The probability of connection decreased from 0.09 to 0.01 with intercell distance (over the range 25-200 mum). Within the same volume, local interneuron (fast-spikingnon-accomodating interneuron, FS)-pyramidal cell connections were about 10 times more numerous, with the majority of connections being reciprocal. The probability of excitatory and inhibitory connections between pyramidal cells and FS interneurons decreased only slightly with distance, being in the range 0.5-0.75. Pyramidal cells in the local network received strong synaptic input during stimulation of afferent fibres in layers 1 and 6. Minimal-like stimulation of layer 1 or layer 6 inputs simultaneously induced postsynaptic potentials in connected pyramidal cells as well as in pyramidal-FS cell pairs. These inputs readily induced firing of pyramidal cells, although synaptically connected cells displayed different firing patterns. Unitary EPSPs in pyramidal-pyramidal cell pairs did not detectably alter cell firing. FS interneurons fire simultaneously with pyramidal cells. In pyramidal-FS cell pairs, both unitary EPSPs and IPSPs efficiently modulated cell firing patterns. We suggest that computation in the local network may proceed not only by direct pyramidal-pyramidal cell communication but also via local interneurons. With such a high degree of connectivity with surrounding pyramidal cells, local interneurons are ideally poised to both coordinate and expand the local pyramidal cell network via pyramidal-interneuron-pyramidal communication.