Anne ALBRECHT "Fear memory under circadian strain: hippocampal circuit modulation by orexin"

Fear memory consolidation and retrieval are coupled to the circadian rhythm. Circadian strains such as sleep deprivation, shift work or jet lag can impair fear memory by disturbing hippocampal functions and its interaction with the prefrontal cortex. Orexinergic neurons of the hypothalamus, a central component of the wake-promoting system, target the hippocampus and its related network structures and may alleviate the impact of circadian strains on fear memory. In this talk, I will demonstrate that circuits in the hippocampal dentate gyrus as well as interconnected structures such as the supramammillary nucleus are susceptible to orexinergic modulation. We will provide evidence for shifts in the activation of these circuits by acute circadian strain and investigate the consequences of orexinergic modulation of these circuits. This project provides insights into the neurocognitive circuits regulating fear memory strength and their mobilisation by orexin.