A recent study used high-resolution scans to observe brain connections at a very detailed level. These pathways create a network that keeps the human brain awake and conscious even during rest. This network is called the ‘default ascending arousal network.’ For the past 10 years, brain imaging studies have focused on mapping the cortical networks responsible for awareness, but the subcortical networks responsible for maintaining wakefulness have been difficult to map due to their small size and complex structure.
A study using magnetic resonance imaging (MRI) was conducted to map a subcortical brain network responsible for integrating arousal and awareness in human consciousness. The study integrated high-resolution structural and functional connectivity data to reveal these findings. The paper, titled “Multimodal MRI reveals brainstem connections that sustain wakefulness in human consciousness,” was published in Science Translational Medicine by a group of researchers from Massachusetts General Hospital and Boston Children’s Hospital.
Researchers have proposed a new map of a brain network that is essential for human consciousness.
The study used advanced scans to visualize brain connections at an incredibly detailed level, revealing previously undiscovered pathways connecting various regions of the brain.
These pathways make up a “default ascending arousal network” that helps maintain wakefulness in the awake, conscious human brain. The idea of a “default” network is based on the concept that specific networks in the brain are most active during certain functions.The brain exhibits different patterns of activity when it is at rest compared to when it is engaged in specific tasks. A study used 7 Tesla resting-state functional MRI data from the Human Connectome Project to explore the characteristics of the default brain network. The analysis uncovered connections between the subcortical default ascending arousal network and the cortical default mode network, which is responsible for self-awareness in the resting, conscious brain. The combination of structural and functional connectivity maps offers a neuroanatomic foundation for understanding these processes.The researchers have published MRI data, brain mapping techniques, and a new Harvard Ascending Arousal Network Atlas to assist in future endeavors to map the connections within human consciousness.
Brian Edlow, MD, the lead author and co-director of Mass General Neuroscience, as well as the associate director of the Center for Neurotechnology and Neurorecovery (CNTR) at Mass General, states that their objective was to map a crucial human brain network related to consciousness. This will provide clinicians with improved tools to identify, predict, and facilitate the recovery of consciousness in patients with severe brain injuries.Associate professor of Neurology at Harvard Medical School and a Chen Institute MGH Research Scholar 2023-2028. Dr. Edlow explains that their findings indicate that stimulating the ventral tegmental area’s dopaminergic pathways could potentially aid in the recovery of coma patients, as this central node is linked to many crucial regions of the brain related to consciousness. Senior author Hannah Kinney, MD, Professor Emerita at Boston Children’s Hospital and Harvard Medical School, also notes that the human brain connections they discovered can serve as a guide for gaining a deeper understanding of various neurological conditions.urological disorders related to changes in consciousness, such as coma, seizures, and sudden infant death syndrome (SIDS). The authors are currently engaged in clinical trials to stimulate the default ascending arousal network in patients who have experienced a coma due to traumatic brain injury, with the aim of reactivating the network and restoring consciousness.
