Topic: anesthesia

Neural activity in sensory cortex combines stimulus responses and ongoing activity, but it remains unclear whether they reflect the same underlying dynamics or separate processes. Here we show that during wakefulness, the neuronal assemblies evoked by sounds in the auditory cortex and thalamus are specific to the stimulus and distinct from the assemblies observed in ongoing activity. In contrast, during anesthesia, evoked assemblies are indistinguishable from ongoing assemblies in the cortex, while they remain distinct in the thalamus. A strong remapping of sensory responses accompanies this d

Transcranial focused ultrasound (tFUS) is a non-invasive neurostimulation modality capable of targeting deep brain regions with high spatial resolution. Despite its growing popularity, there is still a need to investigate the direct effect of its focused mechanical waves on the activation of the neuronal populations in specific brain areas in addition to the role that each of its physical parameters plays in this process. For this purpose, we have used fluorescent calcium imaging with fiber photometry to visualize the changes in the neuronal activity upon stimulation with tFUS. Fiber photometr

Sleep is a physiological state often associated with a cutoff from the external world, and especially loss of conscious perception of sensory stimuli. Even though brain signatures of sleep have been studied for years, the mechanisms that prevent sensory information from reaching consciousness remain to be elucidated. Recently published findings suggest that the loss of perception experienced in anesthesia may be due to neurons population activity coding of stimuli in the cortex collapsing into the spontaneous activity subspace, therefore reflecting internally generated dynamics rather than evo

The variability in brain activity and dynamical regimes across diverse levels of consciousness have been extensively investigated. However, a comprehensive quantification of these variations is still lacking.This work uses multiple computational strategies to study the mesoscale dynamics and the network topology of neuronal ensembles across different levels of consciousness, focusing on wakefulness, anesthesia, and awakening. The data were acquired by two chronically implanted multielectrode arrays (Utah 96), placed in the dorsal prefrontal cortex (dPFC) and dorsal premotor cortex (PMd) of two

Early perspectives on the brain's visual system suggested that it is comprised of separate information streams, each specializing in processing distinct visual features. In this scheme, neurons in lower regions conduct local analyses of image elements within their small receptive fields, while neurons in higher visual areas represent the visual scene in a more global and abstract manner (e.g., by identification and segmentation of objects). However, when processing ambiguous visual stimuli, such as those generated by Kanizsa figures, the local analysis by lower levels might be insufficient for

During NREM sleep and anesthesia, the cerebral cortex generates low-frequency synchronized activity, known as Slow Wave Oscillation (SWO). In this brain state, cortical neurons alternate between hyperpolarized Down states and depolarized Up states, which will travel from their source through cortico-cortical connections along the whole cortex. This makes the SWO an ideal model to understand cortico-cortical communication and disentangle local properties from those that are controlled by the network state.In this project, we built a computational model of coupled cortical populations under the