Topic: Sharp wave ripples

Sharp wave ripples are brief, highly synchronous bursts of activity in the local field potential and population activity of the hippocampus. They occur predominantly during periods of inactivity and are crucial for the transfer of short-term memories in the hippocampus to long-term memories in the cortex. How this process exactly takes place at the neuronal level, however, is still largely unknown. To answer this question, we leveraged a large publicly available dataset of simultaneous Neuropixels recordings across the brain from the International Brain Laboratory collaboration. We analyzed 74

Sharp wave ripples (SWR) represent synchronized activity of neuronal population in the mammalian hippocampus. They are thought to be associated with memory reactivation, transfer, and consolidation during sleep and awake immobility. In adults, it was shown that some subtypes of SWR are triggering precise activation across cortical areas accompanied by strong inhibition in subcortical areas (Logothetis et. al. 2012, Pedrosa et. al 2022) while other subtypes preferentially activates neuromodulatory structures such as the dorsal raphe nucleus and the locus coeruleus (Ramirez-Villega et. al 2015).

Alzheimer's disease (AD) is a progressive neurodegenerative condition characterized by a significant decline in episodic memory. More recent research indicates that impairments in spatial navigation may serve as a more sensitive biomarker for AD compared to episodic memory alterations. To study the cellular mechanisms behind spatial memory and navigation deficits in AD we used the APP/PS1 mouse model of amyloidosis. To assess spatial memory updating, a non-stressful paradigm called Objects in Updated Locations (OUL) was employed. This task allows the quantification of the different times of ex