Wolcott Nora S, Redman William T, Karpinska Marie, Jacobs Emily G, Goard Michael J
Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
Interdepartmental Graduate Program in Dynamical Neuroscience, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
bioRxiv. 2024 Aug 3:2024.08.02.606418. doi: 10.1101/2024.08.02.606418.
Histological evidence suggests that the estrous cycle exerts a powerful effect on CA1 neurons in mammalian hippocampus. Decades have passed since this landmark observation, yet how the estrous cycle shapes dendritic spine dynamics and hippocampal spatial coding remains a mystery. Here, we used a custom hippocampal microperiscope and two-photon calcium imaging to track CA1 pyramidal neurons in female mice over multiple cycles. Estrous cycle stage had a potent effect on spine dynamics, with heightened density during periods of greater estradiol (proestrus). These morphological changes were accompanied by greater somatodendritic coupling and increased infiltration of back-propagating action potentials into the apical dendrite. Finally, tracking CA1 response properties during navigation revealed enhanced place field stability during proestrus, evident at the single-cell and population level. These results establish the estrous cycle as a driver of large-scale structural and functional plasticity in hippocampal circuits essential for learning and memory.
组织学证据表明，发情周期对哺乳动物海马体中的CA1神经元具有强大的影响。自这一具有里程碑意义的观察结果出现以来，几十年过去了，但发情周期如何塑造树突棘动力学和海马体空间编码仍是一个谜。在这里，我们使用定制的海马体微型显微镜和双光子钙成像技术，在多个周期内追踪雌性小鼠的CA1锥体神经元。发情周期阶段对树突棘动力学有显著影响，在雌二醇水平较高的时期（发情前期）密度增加。这些形态学变化伴随着更强的体树突耦合以及反向传播动作电位向顶端树突的渗透增加。最后，在导航过程中追踪CA1反应特性发现，发情前期位置场稳定性增强，在单细胞和群体水平上均很明显。这些结果表明，发情周期是海马体回路中大规模结构和功能可塑性的驱动因素，而海马体回路对学习和记忆至关重要。
