Biology subjects

Carrion-Falgarona, S.

Publications and source records attributed to Carrion-Falgarona, S..

3 recordsLinked to original sources

bioRxiv2026

Brain-heart interactions predict brain activity recovery after systemic anoxia

Global cerebral anoxia is a leading cause of death and resuscitated patients often remain persistently affected by neurological deficits. While previous studies suggest that brain-heart electrophysiological interactions may predict severity and prognosis after hypoxic brain injury coma, little is known about the brain-heart dynamics at near-death. Gaining insight into these mechanisms is crucial for developing targeted interventions in critical conditions. Using a rodent model of reversible systemic anoxia (n=29, male and female rats), we investigated whether brain-heart interactions during the asphyxia onset could predict the return of brain electrical activities after resuscitation. Electrophysiological recordings confirmed that cerebral activity declines following asphyxia, coinciding with increased heart rate variability. Notably, the strong coupling between cardiac parasympathetic activity and high-frequency brain activity in the somatosensory cortex and hippocampus serves as a key predictor of a survival. Our study underscores the potential involvement of the brain-heart axis in the physiology of dying and the potential prognostic significance of the underlying mechanisms, paving the way for translational research into critical care, based on new characterizations of cardiac reflexes and brain-heart interactions. Significance StatementUnderstanding the physiological processes that determine survival and recovery following systemic anoxia is critical for improving outcomes in critical care. This study reveals that brain-heart dynamics during the onset of systemic anoxia relate to survival after resuscitation. In particular, the coupling between parasympathetic cardiac activity and high-frequency brain signals. Using a reversible anoxia rodent model, we demonstrate that early brain-heart interactions are not merely consequences of anoxia, but active markers of resilience. These findings offer a novel framework for understanding the physiology of dying and to ultimately developing prognostic tools based on real-time physiological monitoring.

neuroscience↗

bioRxiv2024

Measuring the time-dependent effects of dobutamine on the modulations of cardiac activity in rats

Assessing cardiac dynamics over time is essential for understanding cardiovascular health and its parallel patterns of activity with the brain. We present a methodology to estimate the time-resolved sympathetic and parasympathetic modulations of cardiac dynamics, specifically tailored for the rat heart. To evaluate the performance of our method, we study a dataset comprising spontaneously hypertensive rats and Wistar-Kyoto rats. These rats were administered dobutamine to elicit autonomic dynamics. The results obtained from our method demonstrated accurate time-resolved depiction of sympathetic reactivity induced by dobutamine administration. These responses closely resembled the expected autonomic alterations observed during physical exercise conditions, albeit emulated pharmacologically. We further compared our method with standard measures of low-frequency (LF) and high-frequency (HF) components, which are commonly used, although debated, for sympathetic and parasympathetic activity estimation. The comparisons with LF and HF measures further confirmed the effectiveness of our method in better capturing autonomic changes in rat cardiac dynamics. Our findings highlight the potential of our adapted method for time-resolved analysis in future clinical and translational studies involving rodents models. The validation of our approach in animal models opens new avenues for investigating the relationship between ongoing changes in cardiac activity and parallel changes in brain dynamics. Such investigations are crucial for advancing our understanding of the brain-heart connection, particularly in cases involving neurodegeneration, brain injuries, and cardiovascular conditions. Key points- We developed a method for time-resolved estimation of sympathetic and parasympathetic modulations in rat cardiac dynamics, validated against standard LF and HF measures. - We used a cohort of spontaneously hypertensive rats and Wistar-Kyoto rats, with dobutamine administration to induce autonomic responses. - Our method accurately depicted time-resolved sympathetic reactivity similar to autonomic changes during physical exercise. - Our findings suggest potential for future clinical and translational studies on the brain-heart connection, particularly in cardiovascular conditions.

neuroscience↗

bioRxiv2023

Cortical astrocyte N-Methyl-D-Aspartate receptors influence whisker barrel activity and sensory discrimination

Cortical astrocytes encode sensory information through their calcium dynamics, but it remains unclear if modulation of astrocyte calcium transients can change somatosensory circuits and behaviour in vivo. Here, we used a novel knockdown approach to selectively reduce astrocyte N-methyl-D-aspartate receptors (NMDAR). We found that these ionotropic receptors contribute to astrocyte Ca2+ transients encoding sensory information. This was essential for the optimal processing of sensory information in nearby neurons, since a reduction in astrocyte NMDARs caused circuit dysfunction and impaired neuronal responses to stimulation. This led to sensory discrimination deficits in the animal. Overall, our findings show that astrocytes can rapidly respond to glutamatergic transmission via their NMDAR and these receptors are an important component for astrocyte-neuron interactions that regulate cortical sensory discrimination in vivo.

neuroscience↗