Moderate white light exposure enhanced spatial memory retrieval by activating a central amygdala-involved circuit in mice
Mengjuan Shang, Meilun Shen, RuoTong Xu, JingYu Du, Jimeng Zhang, Ding OuYang, Junze Du, Junfeng Hu, Zhi‐Chuan Sun, Bingxia Wang, Qian Han, Yang Hu, YiHong Liu, Yun Guan, Jing Li, Guozhen Guo, Jun-Ling Xing
Abstract
Light exposure can profoundly affect neurological functions and behaviors. Here, we show that short-term exposure to moderate (400 lux) white light during Y-maze test promoted spatial memory retrieval and induced only mild anxiety in mice. This beneficial effect involves the activation of a circuit including neurons in the central amygdala (CeA), locus coeruleus (LC), and dentate gyrus (DG). Specifically, moderate light activated corticotropin-releasing hormone (CRH) positive (+) CeA neurons and induced the release of corticotropin-releasing factor (CRF) from their axon terminals ending in the LC. CRF then activated tyrosine hydroxylase-expressing LC neurons, which send projections to DG and release norepinephrine (NE). NE activated β-adrenergic receptors on CaMKIIα-expressing DG neurons, ultimately promoting spatial memory retrieval. Our study thus demonstrated a specific light scheme that can promote spatial memory without excessive stress, and unraveled the underlying CeA-LC-DG circuit and associated neurochemical mechanisms.