INRAE, UMR 85 Physiologie de la Reproduction et des Comportements, 37380, Nouzilly, France.
CNRS, UMR 7247, 37380, Nouzilly, France.
Sci Rep. 2020 Sep 3;10(1):14620. doi: 10.1038/s41598-020-71680-w.
Chronic stress is a strong modulator of cognitive processes, such as learning and memory. There is, however, great within-individual variation in how an animal perceives and reacts to stressors. These differences in coping with stress modulate the development of stress-induced memory alterations. The present study investigated whether and how chronic stress and individual emotionality interrelate and influence memory performances and brain neurogenesis in birds. For that, we used two lines of Japanese quail (Coturnix japonica) with divergent emotionality levels. Highly (E+) and less (E-) emotional quail were submitted to chronic unpredictable stress (CUS) for 3 weeks and trained in a spatial task and a discrimination task, a form of cue-based memory. E + and E- birds were also used to assess the impact of CUS and emotionality on neurogenesis within the hippocampus and the striatum. CUS negatively impacted spatial memory, and cell proliferation, and survival in the hippocampus. High emotionality was associated with a decreased hippocampal neurogenesis. CUS improved discrimination performances and favored the differentiation of newborn cells into mature neurons in the striatum, specifically in E+ birds. Our results provide evidence that CUS consequences on memory and neural plasticity depends both on the memory system and individual differences in behavior.
慢性应激是认知过程（如学习和记忆）的一个重要调节因素。然而，动物对压力源的感知和反应存在很大的个体内差异。这些应对压力的差异调节了应激诱导的记忆改变的发展。本研究调查了慢性应激和个体情绪性是否以及如何相互关联，并影响鸟类的记忆表现和大脑神经发生。为此，我们使用了两种具有不同情绪水平的日本鹌鹑（Coturnix japonica）品系。高（E+）和低（E-）情绪鹌鹑接受了 3 周的慢性不可预测应激（CUS）处理，并在空间任务和辨别任务（基于线索的记忆形式）中进行了训练。E+和 E-鸟类还被用于评估 CUS 和情绪对海马体和纹状体神经发生的影响。CUS 对空间记忆、海马体中的细胞增殖和存活产生负面影响。高情绪性与海马体神经发生减少有关。CUS 提高了辨别表现，并有利于新生细胞在纹状体中的分化为成熟神经元，特别是在 E+鸟类中。我们的结果提供了证据，表明 CUS 对记忆和神经可塑性的影响既取决于记忆系统，也取决于行为的个体差异。
