Science translational medicine
May 1, 2024
Brian L Edlow, Mark Olchanyi, Holly J Freeman et al.
39 citations
A proposed subcortical arousal network, crucial for wakefulness, has been mapped in the human brain, revealing connections between key areas like the brainstem and hypothalamus. Utilizing data from three neurologically normal individuals' brains and advanced imaging techniques, this study identified pathways linking the default ascending arousal network with the cortical default mode network. Notably, the dopaminergic ventral tegmental area emerged as a central hub connecting these networks. This work enhances our understanding of how arousal and awareness integrate in human consciousness.
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.
Journal of molecular neuroscience : MN
July 12, 2025
Weihao Fan, Yi Ye, Hongkun Yang et al.
1 citation
Ketamine, originally developed as an anesthetic, is now being studied for depression treatment, but its addictive potential is a growing concern. This research used a mouse model of ketamine-induced conditioned place preference (CPP) to investigate changes in the striatum, a brain region involved in reward. Advanced metabolomics techniques revealed that ketamine abuse alters striatal metabolites, affecting pathways related to arginine synthesis, purine metabolism, and morphine addiction. Specifically, ketamine increased the neurotransmitter kynurenine (Kyn) and decreased dopamine (DA) in the striatum. These disturbances in Kyn and DA metabolism may underlie the addictive behaviors seen in the CPP model, offering new insights into ketamine addiction mechanisms.
bioRxiv Preprint Server
July 13, 2023
Brian L. Edlow, Mark Olchanyi, Holly J. Freeman et al.
preprint
Consciousness depends on both arousal (wakefulness) and awareness. While cortical networks for awareness are well studied, the subcortical networks supporting arousal are less understood. By combining ex vivo diffusion MRI, immunohistochemistry, and in vivo 7 Tesla functional MRI in three human brain specimens, the authors identified a default ascending arousal network (dAAN) in the brainstem, hypothalamus, thalamus, and basal forebrain. They mapped connections within the dAAN and between the dAAN and the cortical default mode network (DMN), suggesting a structural basis for integrating arousal and awareness. The data and methods are released to aid further mapping of human consciousness.