MI neuronal responses to peripheral whisker stimulation: Relationship to neuronal activity in SI barrels and septa
MI neuronal responses to peripheral whisker stimulation: Relationship to neuronal activity in SI barrels and septa
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DOI：
10.1152/jn.90327.2008
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发表时间：
2008-07-01
影响因子：
2.5
通讯作者：
Alloway, Kevin D.
中科院分区：
文献类型：
--
作者：
Chakrabarti, Shubhodeep;Zhang, Mengliang;Alloway, Kevin D.
啮齿类动物初级运动（MI）皮层的须区接收与初级体感（SI）皮层须区第四层间隔对齐的神经元的密集投射。为了比较心肌梗死中须诱导的反应与间隔和相邻脑筒区的SI反应，我们在麻醉大鼠中采用了几种实验方法。SI和周围皮层的可逆失活将MI须区须诱导的反应幅度抑制了80%。随后对须垫的电或机械刺激的MI反应进行层流分析，发现最敏感的MI神经元位于pia以下>= 1.0 mm。当在须的低频（2 Hz）偏转时，同时记录SI的第四层神经元和深度MI神经元时，SI桶中的神经元比MI桶中的神经元反应早2-6 ms。桶神经元在所有刺激频率下都表现出相似的反应潜伏期，但当须在8 Hz偏转时，MI和SI隔的反应潜伏期显著增加。最后，SI和MI神经元活动的互相关分析显示，间隔-MI神经元对之间的时间锁定协调量大于桶-MI神经元对之间的时间锁定协调量。这些结果表明，体感觉皮质皮层输入到脑内皮层传递的信息是由中隔电路处理的。
The whisker region in the rodent primary motor (MI) cortex receives dense projections from neurons aligned with the layer IV septa in the whisker region of the primary somatosensory (SI) cortex. To compare whisker-induced responses in MI with respect to the SI responses in the septa and adjoining barrel regions, we used several experimental approaches in anesthetized rats. Reversible inactivation of SI and the surrounding cortex suppressed the magnitude of whisker-induced responses in the MI whisker region by 80%. Subsequent laminar analysis of MI responses to electrical or mechanical stimulation of the whisker pad revealed that the most responsive MI neurons were located >= 1.0 mm below the pia. When layer IV neurons in SI were recorded simultaneously with deep MI neurons during low-frequency (2-Hz) deflections of the whiskers, the neurons in the SI barrels responded 2-6 ms earlier than those in MI. Barrel neurons displayed similar response latencies at all stimulus frequencies, but the response latencies in MI and the SI septa increased significantly when the whiskers were deflected at frequencies of 8 Hz. Finally, cross-correlation analysis of neuronal activity in SI and MI revealed greater amounts of time-locked coordination among septa-MI neuron pairs than among barrel-MI neuron pairs. These results suggest that the somatosensory corticocortical inputs to MI cortex convey information processed by the SI septal circuits.