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Hernandez, P. M.

Publications and source records attributed to Hernandez, P. M..

2 recordsLinked to original sources

SFRP1 drives glycolytic activation in astrocytes during neuroinflammation

Astrocytes and microglia maintain brain homeostasis and respond to inflammation through functions coordinated by molecular mediators they produce. Growing evidence shows that cellular metabolism is key to how these cells adapt to challenges. However, little is known about what drives glial metabolic reprogramming or whether molecules involved in astrocyte- microglia crosstalk also regulate this process. Here, we explored this question focusing on Secreted Frizzled-Related Protein 1 (SFRP1). SFRP1 is an astrocyte-derived factor induced by inflammatory cues and overexpressed in neurodegeneration, which fosters microglial response to inflammation through NF-{kappa}B/HIF-dependent programs. We combined mitochondrial morphometry (MitoTracker Red and MiNA analysis) with Seahorse extracellular flux assays (Mito Stress Test) to determine whether SFRP1 modulates glial bioenergetics in primary cultures of astrocytes and microglia from wild-type and Sfrp1-/- mice. We report that SFRP1 acts as a driver of astrocytic metabolic activation, preferentially enhancing glycolysis over mitochondrial respiration. This effect is most pronounced during inflammation, when oxidative phosphorylation is restricted and SFRP1 enhances glycolytic flexibility to sustain energy demands. By contrast, microglia showed the expected LPS-driven glycolytic shift with minimal dependence on SFRP1 under monoculture conditions. These findings position SFRP1 as a candidate regulator of astrocyte-centered metabolic tuning during neuroinflammation, with implications for disorders such as Alzheimers disease, in which SFRP1 is elevated.

neuroscience↗

Sleep-state dependent cerebellar processing in adult mice

The cerebellum is important for motor performance and adaptation as well as cognition. Sleep is essential for optimizing of all these functions, but it remains to be elucidated how sleep affects cerebellar processing. It has been suggested that sleep periods with muscle twitches entrain the cerebellum with a copy of motor commands and subsequent sensory feedback signals, to develop predictive coding of movements. If this hypothesis is correct, one expects phasic correlations between the muscle twitches and specific features of the electro-encephalography (EEG) recordings in the cerebellum during various sleep stages as well as the climbing fiber activity in the cerebellar cortex, the modulation of which is relayed from the cerebral cortex via mesodiencephalic junction and inferior olive. Here we provide evidence for coherent correlations between cerebellar and cerebral cortical sleep spindles, twitches as well as patterns of climbing fiber activity. Our data are compatible with the novel concept that muscle twitches evoke complex spike synchronicity during NREM, which in turn affects cerebellar spindle activity and cerebellar-cortical information flow, thereby entraining an internal forward model.

neuroscience↗