Tomar Anupratap, Polygalov Denis, McHugh Thomas J
Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Saitama, Japan.
Front Behav Neurosci. 2021 Jul 20;15:710725. doi: 10.3389/fnbeh.2021.710725. eCollection 2021.
Chronic and acute stress differentially affect behavior as well as the structural integrity of the hippocampus, a key brain region involved in cognition and memory. However, it remains unclear if and how the facilitatory effects of acute stress on hippocampal information coding are disrupted as the stress becomes chronic. To examine this, we compared the impact of acute and chronic stress on neural activity in the CA1 subregion of male mice subjected to a chronic immobilization stress (CIS) paradigm. We observed that following first exposure to stress (acute stress), the spatial information encoded in the hippocampus sharpened, and the neurons became increasingly tuned to the underlying theta oscillations in the local field potential (LFP). However, following repeated exposure to the same stress (chronic stress), spatial tuning was poorer and the power of both the slow-gamma (30-50 Hz) and fast-gamma (55-90 Hz) oscillations, which correlate with excitatory inputs into the region, decreased. These results support the idea that acute and chronic stress differentially affect neural computations carried out by hippocampal circuits and suggest that acute stress may improve cognitive processing.
慢性应激和急性应激对行为以及海马体的结构完整性有不同影响，海马体是参与认知和记忆的关键脑区。然而，随着应激变为慢性，急性应激对海马体信息编码的促进作用是否以及如何受到破坏仍不清楚。为了研究这一点，我们比较了急性应激和慢性应激对接受慢性束缚应激（CIS）范式的雄性小鼠CA1亚区神经活动的影响。我们观察到，首次暴露于应激（急性应激）后，海马体中编码的空间信息变得更加清晰，并且神经元对局部场电位（LFP）中潜在的θ振荡的调谐越来越强。然而，在反复暴露于相同应激（慢性应激）后，空间调谐变差，与该区域兴奋性输入相关的慢γ（30 - 50赫兹）和快γ（55 - 90赫兹）振荡的功率均下降。这些结果支持了急性应激和慢性应激对海马体回路进行的神经计算有不同影响这一观点，并表明急性应激可能改善认知加工。
