Theta-modulated feedforward network generates rate and phase coded firing in the entorhino-hippocampal system
Theta-modulated feedforward network generates rate and phase coded firing in the entorhino-hippocampal system
复制标题
Theta 调制前馈网络在内鼻海马系统中生成速率和相位编码放电
DOI：
--
复制
发表时间：
2004
影响因子：
--
通讯作者：
P. Érdi
中科院分区：
文献类型：
--
作者：
M. Lengyel;P. Érdi
在自由活动的大鼠中，海马和其唯一的皮质输入区域内嗅皮质的主要细胞表现出位置特异性活动。虽然内嗅细胞具有广泛调谐的位置场，但海马位置场更局部化，不仅决定位置细胞尖峰的速率，而且决定位置细胞尖峰的时间。几个模型已经成功地试图解释这种微调利用海马CA 3区的经常性侧支所提供的海马内吸引子网络动力学。最近的实验证据表明，CA 1的位置细胞保持其调谐曲线，即使在没有输入从CA 3。我们提出了一个模型，其中内嗅和海马锥体细胞群只通过前馈连接。在我们的系统中，突触传递是由一类特异性抑制内鼻-海马通路的中间神经元门控的。Theta节律调节每个组成部分的活动。我们的研究结果表明，节律性分流抑制赋予内嗅细胞一种新型的时间代码传达的相位抖动的个人尖峰。这将粗调的特定位置的活动内嗅皮层速度依赖性突触后兴奋，因此，提供了海马位置细胞的输入，最近已被提出，以占他们的速率和相位编码发射。海马位置场是通过这种机制产生的，也显示出对紧张性抑制水平的变化是稳健的。
Principal cells of the hippocampus and of its only cortical input region, the entorhinal cortex exhibit place specific activity in the freely moving rat. While entorhinal cells have widely tuned place fields, hippocampal place fields are more localized and determine not only the rate but also the timing of place cell spikes. Several models have successfully attempted to explain this fine tuning making use of intrahippocampal attractor network dynamics provided by the recurrent collaterals of hippocampal area CA3. Recent experimental evidence shows that CA1 place cells preserve their tuning curves even in the absence of input from CA3. We propose a model in which entorhinal and hippocampal pyramidal cell populations are only connected via feedforward connections. Synaptic transmission in our system is gated by a class of interneurons inhibiting specifically the entorhino-hippocampal pathway. Theta rhythm modulates the activity of each component. Our results show that rhythmic shunting inhibition endows entorhinal cells with a novel type of temporal code conveyed by the phase jitter of individual spikes. This converts coarsely tuned place-specific activity in the entorhinal cortex to velocity-dependent postsynaptic excitation and, thus, provides hippocampal place cells with an input that has recently been proposed to account for their rate and phase coded firing. Hippocampal place fields are generated through this mechanism and also shown to be robust against variations in the level of tonic inhibition.
登录
查看更多内容
影响因子：
2.5
作者：
Frank, LM;Brown, EN;Wilson, MA
通讯作者：
Wilson, MA
DOI：
10.1073/pnas.94.16.8918
发表时间：
1997-08-05
影响因子：
11.1
作者：
Mehta, MR;Barnes, CA;McNaughton, BL
通讯作者：
McNaughton, BL
影响因子：
2.5
作者：
Wallenstein, GV;Hasselmo, ME
通讯作者：
Hasselmo, ME
影响因子：
2
作者：
Jensen, O;Lisman, JE
通讯作者：
Lisman, JE