Dynamics of robust pattern separability in the hippocampal dentate gyrus.
Dynamics of robust pattern separability in the hippocampal dentate gyrus.
复制标题
海马齿状回稳健模式可分离性的动力学。
DOI：
10.1002/hipo.22546
复制
发表时间：
2016
期刊：
影响因子：
3.5
通讯作者：
Strowbridge,BenW
中科院分区：
文献类型：
--
作者：
Zylberberg,Joel;Hyde,RobertA;Strowbridge,BenW
齿状回（DG）被认为对从内嗅皮层接收的输入执行模式分离，使得DG形成不同输入模式的不同表征。然而，神经元的反应是可变的，这种可变性有可能混淆不同输入的表示，从而阻碍模式分离功能。这种变异性对于DG等组织尤其成问题，其中响应在刺激后可持续数十秒：长的响应持续时间允许来自许多不同来源的变异性累积。为了了解DG如何能够鲁棒地编码不同的输入模式，我们研究了最近开发的体外海马DG制备，产生持续的响应瞬态电刺激。刺激后10-20 s，反应指示所施加的刺激模式，即使反应显示出显著的试验间变异性。分析诱发反应的动态轨迹，我们发现，刺激后，神经反应遵循不同的路径通过空间的可能的神经激活，与不同的路径与每个刺激模式。神经反应的试验间变异性使反应沿着这些路径而不是在它们之间移动，从而保持了输入模式的可分离性。在可能的神经激活空间上更各向同性地重新分配变异性的操作阻碍了模式分离功能。因此，我们得出结论，神经元的可变性限制在这些一维路径上减轻了可变性对模式编码的影响，因此，可能是DG鲁棒编码输入模式的能力的一个重要方面。© 2015威利期刊公司.
The dentate gyrus (DG) is thought to perform pattern separation on inputs received from the entorhinal cortex, such that the DG forms distinct representations of different input patterns. Neuronal responses, however, are known to be variable, and that variability has the potential to confuse the representations of different inputs, thereby hindering the pattern separation function. This variability can be especially problematic for tissues such as the DG, in which the responses can persist for tens of seconds following stimulation: the long response duration allows for variability from many different sources to accumulate. To understand how the DG can robustly encode different input patterns, we investigated a recently developedin vitrohippocampal DG preparation that generates persistent responses to transient electrical stimulation. For 10–20 s after stimulation, the responses are indicative of the pattern of stimulation that was applied, even though the responses exhibit significant trial‐to‐trial variability. Analyzing the dynamical trajectories of the evoked responses, we found that, following stimulation, the neural responses follow distinct paths through the space of possible neural activations, with a different path associated with each stimulation pattern. The neural responses' trial‐to‐trial variability shifts the responsesalongthese paths rather thanbetweenthem, maintaining the separability of the input patterns. Manipulations that redistributed the variability more isotropically over the space of possible neural activations impeded the pattern separation function. Consequently, we conclude that the confinement of neuronal variability to these one‐dimensional paths mitigates the impacts of variability on pattern encoding and, thus, may be an important aspect of the DG's ability to robustly encode input patterns. © 2015 Wiley Periodicals, Inc.