Neuron-vascular Coupling in the Amygdala Control Behavioral State of Stress-induced Defecation and Innate Fear Retention

Abstract

AbstractProper cerebral function depends on intact neurovascular coupling (NVC), a conservative biological process in mammals that can effectively and spatiotemporally regulate cerebral blood distribution. The amygdala is a critical cerebral region for regulating emotion and stress-related behaviors. However, how NVC participates in advanced cerebral function and the consequences of NVC dysfunction in the amygdala remain unclear. The lack of cellular-specific transgenic models and non-specific drug administration mainly limited previous studies on NVC. Moreover, almost all papers take the function of hyperemia as the readout of NVC, but the advanced significance of functional hyperemia still needs to be discovered. Hence, the findings could have been more robust. In this study, we broadly used cellular-specific transgenic models to manipulate NVC and combined them with the chemogenetic strategy to reveal NVC-related cerebral advanced function. This study confirmed that GLRB loss in mural cells leads to NVC enhancement, the first report of a transgenic NVC enhancement model. Also, we are the first to use the transgenic model to clarify that COX-2 in neurons contributes to NVC regulation. The major work of this study is using arterial smooth muscle cells (aSMCs) NR2D conditional knockout model as a presentative NVC dysfunction model to find that NVC dysfunction in the amygdala context-dependently leads to shorter innate fear retention and increased stress-induced defecation. Through chemogenetic inhibition of neurons in the amygdala can correct increased stress-induced defecation in NVC dysfunction mice. Besides, during the behavioral assay, we first report the correlation pattern between pupil size and locomotion during the virtual predator stimulation. Last, we found that caldesmon is the downstream protein of NR2D in aSMCs to regulate NVC, and the interaction site of NR2D and caldesmon may become a drug target for NVC-initiated mental disorders.