Theta Modulation in the Medial and the Lateral Entorhinal Cortices
Theta Modulation in the Medial and the Lateral Entorhinal Cortices
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DOI：
10.1152/jn.01141.2009
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发表时间：
2010-08-01
影响因子：
2.5
通讯作者：
Knierim, James J.
中科院分区：
文献类型：
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作者：
Deshmukh, Sachin S.;Yoganarasimha, D.;Knierim, James J.
Deshmukh SS，Yoganarasimha D，Voicu H，Zererim JJ.内侧和外侧内嗅皮质的θ调制。J Neurophysiol 104：994-1006，2010.首次发表于2010年5月26日; doi：10.1152/jn.01141.2009。海马神经元表现出强烈的调制theta频率振荡。这种调制被认为是重要的，不仅在海马系统中的信息的时间编码和解码，而且在突触可塑性的生理机制操作的时间尺度上的神经元活动的时间顺序。内侧内嗅皮层（MEC），海马的两个主要皮质输入之一，是已知的显示θ调制。在这里，我们表明，在其他主要的皮质输入到海马，外侧内嗅皮质（LEC）的局部场电位（LFPs），显示较弱的θ振荡比MEC中所示。LEC中的神经元也显示出比MEC中的神经元更弱的θ调制。这些研究结果表明，LEC输入整合到海马的代表性在质量上不同的方式比MEC的输入。此外，MEC网格细胞增加其周期性的空间放电模式的规模沿着背腹轴，对应于增加大小的位置字段沿着海马的隔颞轴。我们在这里展示了MEC神经放电跳过交替θ周期的趋势的相应梯度。我们提出了一个简单的模型，基于干扰的三角洲振荡与θ振荡来解释这种行为。
Deshmukh SS, Yoganarasimha D, Voicu H, Knierim JJ. Theta modulation in the medial and the lateral entorhinal cortices. J Neurophysiol 104: 994-1006, 2010. First published May 26, 2010; doi: 10.1152/jn.01141.2009. Hippocampal neurons show a strong modulation by theta frequency oscillations. This modulation is thought to be important not only for temporal encoding and decoding of information in the hippocampal system, but also for temporal ordering of neuronal activities on timescales at which physiological mechanisms of synaptic plasticity operate. The medial entorhinal cortex (MEC), one of the two major cortical inputs to the hippocampus, is known to show theta modulation. Here, we show that the local field potentials (LFPs) in the other major cortical input to the hippocampus, the lateral entorhinal cortex (LEC), show weaker theta oscillations than those shown in the MEC. Neurons in LEC also show weaker theta modulation than that of neurons in MEC. These findings suggest that LEC inputs are integrated into hippocampal representations in a qualitatively different manner than the MEC inputs. Furthermore, MEC grid cells increase the scale of their periodic spatial firing patterns along the dorsoventral axis, corresponding to the increasing size of place fields along the septotemporal axis of the hippocampus. We show here a corresponding gradient in the tendency of MEC neural firing to skip alternate theta cycles. We propose a simple model based on interference of delta oscillations with theta oscillations to explain this behavior.