Somogyi Peter, Katona Linda, Klausberger Thomas, Lasztóczi Bálint, Viney Tim J
Medical Research Council, Anatomical Neuropharmacology Unit, Department of Pharmacology, Oxford University, , Mansfield Road, Oxford OX1 3TH, UK.
Philos Trans R Soc Lond B Biol Sci. 2013 Dec 23;369(1635):20120518. doi: 10.1098/rstb.2012.0518. Print 2014 Feb 5.
The behaviour-contingent rhythmic synchronization of neuronal activity is reported by local field potential oscillations in the theta, gamma and sharp wave-related ripple (SWR) frequency ranges. In the hippocampus, pyramidal cell assemblies representing temporal sequences are coordinated by GABAergic interneurons selectively innervating specific postsynaptic domains, and discharging phase locked to network oscillations. We compare the cellular network dynamics in the CA1 and CA3 areas recorded with or without anaesthesia. All parts of pyramidal cells, except the axon initial segment, receive GABA from multiple interneuron types, each with distinct firing dynamics. The axon initial segment is exclusively innervated by axo-axonic cells, preferentially firing after the peak of the pyramidal layer theta cycle, when pyramidal cells are least active. Axo-axonic cells are inhibited during SWRs, when many pyramidal cells fire synchronously. This dual inverse correlation demonstrates the key inhibitory role of axo-axonic cells. Parvalbumin-expressing basket cells fire phase locked to field gamma activity in both CA1 and CA3, and also strongly increase firing during SWRs, together with dendrite-innervating bistratified cells, phasing pyramidal cell discharge. Subcellular domain-specific GABAergic innervation probably developed for the coordination of multiple glutamatergic inputs on different parts of pyramidal cells through the temporally distinct activity of GABAergic interneurons, which differentially change their firing during different network states.
局部场电位振荡在θ、γ和与尖波相关的涟漪（SWR）频率范围内报告了神经元活动的行为相关节律同步。在海马体中，代表时间序列的锥体细胞组件由选择性支配特定突触后区域的GABA能中间神经元协调，并与网络振荡锁相放电。我们比较了在有无麻醉情况下记录的CA1和CA3区域的细胞网络动力学。除轴突起始段外，锥体细胞的所有部分都从多种类型的中间神经元接收GABA，每种中间神经元都有不同的放电动态。轴突起始段仅由轴-轴突细胞支配，优先在锥体细胞层θ周期的峰值之后放电，此时锥体细胞最不活跃。在许多锥体细胞同步放电的SWR期间，轴-轴突细胞受到抑制。这种双重反相关证明了轴-轴突细胞的关键抑制作用。表达小白蛋白的篮状细胞在CA1和CA3中都与场γ活动锁相放电，并且在SWR期间也强烈增加放电，与支配树突的双分层细胞一起，使锥体细胞放电同步。亚细胞结构域特异性GABA能神经支配可能是为了通过GABA能中间神经元在时间上不同的活动来协调锥体细胞不同部分上的多个谷氨酸能输入而发展而来的，这些中间神经元在不同的网络状态下会有不同的放电变化。
