Biology subjects

Cunen, C.

Publications and source records attributed to Cunen, C..

3 recordsLinked to original sources

bioRxiv2022

Sleep cycle-dependent vascular dynamics enhance perivascular cerebrospinal fluid flow and solute transport

Perivascular spaces (PVS) are important highways for fluid and solute transport in the brain enabling efficient waste clearance during sleep. Using two-photon imaging of naturally sleeping mice we demonstrate sleep cycle-dependent PVS dynamics - slow, large-amplitude oscillations in NREM, a reduction in REM and an enlargement upon awakening at the end of a sleep cycle. By biomechanical modeling we demonstrate that these sleep cycle-dependent PVS dynamics drive fluid flow and solute transport.

neuroscience↗

bioRxiv2021

Impaired astrocytic Ca2+ signalling in awake Alzheimer's disease transgenic mice

Increased astrocytic Ca2+ signaling related to amyloid plaques has been shown in Alzheimers disease mouse models, but to date no reports have characterized behaviorally induced astrocytic Ca2+ signalling in such mice without the confounding effects of anesthesia. Here, we employ an event-based algorithm to assess astrocytic Ca2+ signals in the neocortex of awake-behaving tg-ArcSwe mice and non-transgenic wildtype littermates while monitoring pupil responses and behavior. We demonstrate an attenuated astrocytic Ca2+ response to locomotion and an uncoupling of pupil responses and astrocytic Ca2+ signalling in 15-months old plaque-bearing mice. This points to a potential decoupling of neuromodulatory activation and astrocytic Ca2+ activity, which may account for some of the cognitive dysfunctions observed in Alzheimers disease.

neuroscience↗

bioRxiv2019

Ca2+ signaling in astrocytes is sleep-wake state specific and modulates sleep

Astrocytic Ca2+ signaling has been intensively studied in health and disease but remains uncharacterized in sleep. Here, we employed a novel activity-based algorithm to assess astrocytic Ca2+ signals in the barrel cortex of awake and naturally sleeping mice while monitoring neuronal Ca2+ activity, brain rhythms and behavior. We discovered that Ca2+ signaling in astrocytes exhibits distinct features across the sleep-wake cycle and is reduced in sleep compared to wakefulness. Moreover, an increase in astrocytic Ca2+ signaling precedes transitions from slow-wave sleep to wakefulness, with a peak upon awakening exceeding the levels during whisking and locomotion. Genetic ablation of a key astrocytic Ca2+ signaling pathway resulted in fragmentation of slow-wave sleep, yet increased the frequency of sleep spindles. Our findings suggest a role for astrocytic Ca2+ signaling in modulating sleep.

neuroscience↗