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Hal Blumenfeld

Department of Neurology, Yale University School of Medicine, New Haven, CT, USA; Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, USA. Electronic address: hal.blumenfeld@yale.edu.

4 papers in the library · 14 citations · publishing 2023-2025

Papers

Slow and fast cortical cholinergic arousal is reduced in a mouse model of focal seizures with impaired consciousness.

Cell reports December 24, 2024 Lim-Anna Sieu, Shobhit Singla, Jiayang Liu et al. 8 citations

Focal temporal lobe seizures in humans often cause loss of consciousness accompanied by cortical slow waves similar to deep sleep. Previous rat studies under anesthesia suggested that reduced subcortical arousal depresses cortical function, but could not link conscious behavior to physiology. In an awake mouse model, electrically induced hippocampal seizures impaired behavioral responses to sounds, triggered cortical slow waves, and reduced mean high-frequency cortical activity. Behavioral responses depended on cortical acetylcholine release at two timescales: slow state-related decreases correlated with overall impairment, while fast phasic release corresponded to variable spared or impaired responses per stimulus. These results establish a strong link between decreased cortical arousal and impaired consciousness during focal seizures.

Shared subcortical arousal systems across sensory modalities during transient modulation of attention.

NeuroImage May 15, 2025 Aya Khalaf, Erick Lopez, Jian Li et al. 6 citations

Subcortical arousal systems help control sustained changes in attention and conscious awareness, and recent studies suggest they also influence short-term dynamic modulation of visual attention, but their role across sensory modalities is unclear. Analyzing fMRI data from 1561 participants performing visual, auditory, tactile, and taste perception tasks, a shared circuit of subcortical arousal systems was identified. This circuit shows early transient increases in activity in the midbrain reticular formation and central thalamus across all sensory modalities, with less consistent increases in the pons, hypothalamus, basal forebrain, and basal ganglia. Identifying these networks is critical for understanding normal attention and consciousness and may aid subcortical targeting for therapeutic neuromodulation.

Behavioral unresponsiveness and impaired auditory event-related potentials in the anterior insula during rat absence seizures.

bioRxiv : the preprint server for biology October 7, 2025 Stefan Sumsky, Rory Ashmeade, Jiayang Liu et al. preprint

Absence seizures cause sudden lapses in consciousness accompanied by spike-wave discharges, but how they impair sensory processing is unclear. In a rat model of absence epilepsy, behavioral performance on an auditory task collapsed during seizures, dropping from about 88% correct to less than 1%. However, electrical responses in the primary auditory cortex remained normal. Instead, a novel oscillatory signal in the anterior insular cortex was robust in healthy controls, reduced in epileptic rats between seizures, and nearly absent during seizures. This signal's reduction differed from that seen in satiated, unmotivated states, where waveform structure was preserved. The anterior insula appears to be a critical hub for gating auditory conscious awareness during seizures, offering a potential biomarker and intervention target.

An adversarial collaboration to critically evaluate theories of consciousness

bioRxiv Preprint Server June 23, 2023 Oscar Ferrante, Urszula Gorska-Klimowska, Simon Henin et al. preprint

An open science adversarial collaboration directly juxtaposed Integrated Information Theory (IIT) and Global Neuronal Workspace Theory (GNWT) by investigating neural correlates of visual experience. 256 human subjects viewed suprathreshold stimuli for variable durations while neural activity was measured with fMRI, MEG, and ECoG. Information about conscious content was found in visual, ventro-temporal, and inferior frontal cortex, with sustained responses in occipital and lateral temporal cortex reflecting stimulus duration, and content-specific synchronization between frontal and early visual areas.