Oscillatory dynamics in the hippocampus support dentate gyrus-CA3 coupling
Oscillatory dynamics in the hippocampus support dentate gyrus-CA3 coupling
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DOI：
10.1038/nn.3081
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发表时间：
2012-05-01
影响因子：
25
通讯作者：
Kullmann, Dimitri M.
中科院分区：
文献类型：
--
作者：
Akam, Thomas;Oren, Iris;Kullmann, Dimitri M.
齿状回和海马CA3区的γ振荡在体内表现出可变的一致性，但其机制和与信息流的相关性尚不清楚。我们发现，卡巴胆碱诱导的振荡在大鼠CA3具有双相相位响应曲线，与传入投射中的振荡耦合的能力相一致。通过改变二维动力学系统中的脉冲向量，代表兴奋性和抑制性神经元的相对输入，很好地描述了内在反馈回路或齿状回对刺激的反应差异。对正弦调制的光遗传学刺激的响应证实了CA3网络振荡可以夹带到周期性输入，夹带相位对输入频率的陡峭依赖性。因此，CA3振荡适合于在宽频率范围内与齿状回中的振荡耦合。
Gamma oscillations in the dentate gyrus and hippocampal CA3 show variable coherence in vivo, but the mechanisms and relevance for information flow are unknown. We found that carbachol-induced oscillations in rat CA3 have biphasic phase-response curves, consistent with the ability to couple with oscillations in afferent projections. Differences in response to stimulation of either the intrinsic feedback circuit or the dentate gyrus were well described by varying an impulse vector in a two-dimensional dynamical system, representing the relative input to excitatory and inhibitory neurons. Responses to sinusoidally modulated optogenetic stimulation confirmed that the CA3 network oscillation can entrain to periodic inputs, with a steep dependence of entrainment phase on input frequency. CA3 oscillations are therefore suited to coupling with oscillations in the dentate gyrus over a broad range of frequencies.