Episodic memory refers to the unique set of personal experiences lived. The hippocampus is an essential hub for episodic memory processing. Studies focusing on the role of the hippocampus in learning and the contribution of adult hippocampal neurogenesis to cognition have mostly involved manipulating the brain bilaterally. However, current imaging methods, such as in vivo calcium imaging in freely moving rodents, involve highly invasive procedures that most often target the hippocampus unilaterally. A study in Behavioural Brain Research explores the effects of adeno-associated viral (AAV) vector injections and chronic implantation of a lens in the dorsal hippocampus, both used in calcium imaging, on mouse brain and behavior. Injecting a viral system and then implanting a lens had a small impact on the behavior of adult male C57BL/6 mice in comparison to sham-operated or unoperated control mice. However, AAV injections decreased adult hippocampal neurogenesis when compared to animals injected with PBS. Overall, unilateral surgery to the hippocampus required for in vivo imaging does not affect normal mouse behavior. These findings indicate that the hippocampus is plastic, can reorganize after unilateral damage and still support memory functions.

Original reference: Lehtonen, S. M. et al. Behav. Brain Res. 468,115042 (2024)

情景记忆是指所经历的一组独特的个人经历。海马体是情景记忆处理的重要枢纽。专注于海马体在学习中的作用以及成人海马神经发生对认知的贡献的研究主要涉及双侧操纵大脑。然而，目前的成像方法，例如自由移动的啮齿动物的体内钙成像，涉及高度侵入性的手术，这些手术通常单侧靶向海马体。Behavioural Brain Research 上的一项研究探讨了腺相关病毒 （AAV） 载体注射和在海马背侧慢性植入晶状体（两者都用于钙成像）对小鼠大脑和行为的影响。与假手术或未手术的对照小鼠相比，注射病毒系统然后植入晶状体对成年雄性 C57BL/6 小鼠的行为影响很小。然而，与注射 PBS 的动物相比，AAV 注射减少了成人海马神经发生。总体而言，体内成像所需的海马单侧手术不会影响正常的小鼠行为。这些发现表明海马体是可塑性的，可以在单侧损伤后重组并仍然支持记忆功能。

原始参考资料：Lehtonen， SM 等人 Behav.大脑研究。468.115042 （2024 年）