Intrinsic electrophysiology of mouse corticospinal neurons: a class-specific triad of spike-related properties.
Intrinsic electrophysiology of mouse corticospinal neurons: a class-specific triad of spike-related properties.
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小鼠皮质脊髓神经元的内在电生理学：尖峰相关特性的类特异性三联体。
DOI：
10.1093/cercor/bhs184
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Shepherd,GordonMG
中科院分区：
文献类型：
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作者：
Suter,BenjaminA;Migliore,Michele;Shepherd,GordonMG
皮质脊髓锥体神经元介导运动行为的不同方面。我们测量了来自年轻成年小鼠的初级运动皮层切片中识别出的皮质脊髓神经元的尖峰相关电生理特性。在对电流阶跃的阈上反应中观察到几个一致的特征：1）与邻近的胼胝体投射皮质纹状体神经元相比，皮质脊髓神经元激发相对快的动作电位（AP;半峰宽度0.65 ± 0.13 ms，平均值±标准差[SD]）。皮质脊髓AP宽度介于5 B层的2类抑制性中间神经元之间。AP宽度和其他尖峰波形参数的尖峰到尖峰变异性很低，即使在高达20 Hz的重复发射期间，也就是说，皮质脊髓AP的相对狭窄基本上是频率无关的。2)频率-电流（f-I）关系接近线性。3)AP列车显示出有规律的射击，速率通常保持不变或随着时间的推移而加速。从老年小鼠（最多4个月）或从单独的外侧皮质区（区域B;对应于次级体感皮质）记录的皮质脊髓神经元表现出大致相似的内在特性。我们的研究结果具有解释在体内记录的运动皮层神经元的尖峰波形的影响。这一分析为进一步研究皮质脊髓神经元及其在运动皮质功能中的作用提供了一个框架。
Corticospinal pyramidal neurons mediate diverse aspects of motor behavior. We measured spike-related electrophysiological properties of identified corticospinal neurons in primary motor cortex slices from young adult mice. Several consistent features were observed in the suprathreshold responses to current steps: 1) Corticospinal neurons fired relatively fast action potentials (APs; width at half-maximum 0.65 ± 0.13 ms, mean ± standard deviation [SD]) compared with neighboring callosally projecting corticostriatal neurons. Corticospinal AP width was intermediate between 2 classes of inhibitory interneuron in layer 5B. Spike-to-spike variability in AP width and other spike waveform parameters was low, even during repetitive firing up to 20 Hz, that is, the relative narrowness of corticospinal APs was essentially frequency independent. 2) Frequency–current (f–I) relationships were nearly linear. 3) Trains of APs displayed regular firing, with rates typically staying constant or accelerating over time. Corticospinal neurons recorded from older mice (up to 4 months) or from a separate lateral cortical area (Region B; corresponding to secondary somatosensory cortex) showed generally similar intrinsic properties. Our findings have implications for interpreting spike waveforms of in vivo recorded neurons in the motor cortex. This analysis provides a framework for further biophysical and computational investigations of corticospinal neurons and their roles in motor cortical function.