Hippocampal sharp-wave ripples

Liset de la Prida discusses hippocampal sharp-wave ripples and their relationship to replay and memory. The conversation connects different ripple patterns and neuron types to population activity, asking how particular cells help shape the lower-dimensional dynamics used to describe neural computation.

…It is believed that hippocampal sharp-wave ripples tag memories that are relevant and should be remembered (Yang et al 2024). However, this selection of relevant information must occur already during sensory processing to avoid overloading the system with irrelevant information. The hypothesis of this project is that short bursts of high gamma activity, referred to as cortical ripples to distinguish them from hipp

…waves, thalamocortical spindles and hippocampal sharp waves-ripples, while REM sleep is dominated by hippocampal theta oscillations and ponto-geniculo-occipital (PGO) waves, or pontine waves (“P-waves”) in rodents. Even though their origin from mesopontine cholinergic and glutamatergic nuclei is kn

…including altered gamma oscillations, hippocampal sharp wave-ripples (SWRs) and cortical sleep spindles. Although these oscillations play a role in memory formation and consolidation, it remains poorly understood how abnormal oscillations relate to novel experiences. Here we show that deficits in SWRs are experience-dependent in an AD mouse model. We performed

Cortico-hippocampal interactions during hippocampal sharp-wave ripples (SPW-Rs) play a crucial role in memory consolidation. Hippocampal-dependent memories undergo replay during SPW-Rs, facilitating coordinated ensemble reactivation in the neocortex. This orchestrated mechanism is essential for transferring memory traces from the hippocampus to long-term storage in the neocortex. Following memory consolidation in the neocortex, it is hypothesized that downstream neuronal ensembles are stabilized in diverse cortical regions. The stability of neuronal ensembles across several months has not been

The hippocampus plays an important role in memory formation. Hippocampal sharp wave ripples (SWRs) are critical for memory consolidation, during which a large number of hippocampal pyramidal neurons fire synchronously. Recent studies indicate that the participation of hippocampal pyramidal neurons in SWRs is variable. The variability may be explained by gene expression pattterns. However, there are no adequate methods to comprehensively analyze these molecular properties of a single neuron in the context of its electrophysiological spike patterns. Here, we developed an experimental technique t

…traces are reactivated at the time of hippocampal sharp-wave ripples (SWRs) thought to mediate memory consolidation. Though SWRs have been widely studied within the hippocampus, the ongoing activity within the rest of the brain remains elusive, because technically challenging: electrophysiology cannot easily resolve the whole brain and optical recording techniques have limited access to deep tissue. In a 2012 study, Logothetis and colleague

…Neocortical slow oscillations and hippocampal sharp wave ripples (SPW-R) are the hallmarks of non-rapid eye-movement (NREM) sleep and reflect synchronous activation of neocortical and hippocampal neuronal ensembles, respectively. The dMT is reciprocally connected both with the neocortex and with the hippocampal system, however, little is known about their interaction during sleep. We performed large-scale unit recordings from

Neural activity and bodily functions are inherently rhythmic and related to each other. Hippocampal sharp-wave ripples (SPW-Rs) and dentate spikes (DSs) supporting memory consolidation are most abundant during sleep, especially during non-rapid-eye-movement (NREM) sleep. They also seem to aggregate to a certain phase of the breathing cycle during natural sleep in mice. Here, we aimed to study if the interhemispheric synchrony of SPW-Rs and DSs is affected by neural and bodily state. We recorded dorsal hippocampal local-field potentials and respiration for several hours under urethane anesthesi