A map of brain structures involved in keeping us awake could eventually help to improve people鈥檚 recovery following surgery or comas.
Consciousness has two major components: wakefulness and awareness of both yourself and your surroundings. , the cortex, of the human brain that underpin awareness, but the anatomical basis of wakefulness 鈥� which is regulated in deeper regions of the brain 鈥� is less clear.
Now, at Harvard Medical School and his colleagues have mapped how 18 clusters of nerve cells, or neurons, that were previously found to underlie wakefulness in the brains of mice, rats and cats connect to each other in deep regions of the human brain.
Advertisement
First, the researchers used magnetic resonance imaging (MRI) to scan the brains of three women after they had died at around 60 years of age. This revealed how 10 clusters of neurons in a region at the base of the brain, the brainstem, connect to six clusters in central brain structures called the thalamus and hypothalamus.
The map also revealed how these neural clusters, which had previously been associated with wakefulness, link to two other clusters in a region in the front of the brain called the basal forebrain.
Next, the team traced how these clusters connected with outer regions of the brain that are known to regulate awareness. By combining these findings with brain activity data previously collected from 84 people while they were awake, the team mapped how electrical signals travel between all 18 of these clusters.
鈥淭he findings shed new light on connectivity from the brainstem to the rest of the brain, with the potential to revolutionise our understanding of awareness, human consciousness and a range of neurological and psychiatric conditions,鈥� says at the University of Cambridge.
This map could help us understand how conditions such as being in a coma or delirium (sudden confusion) following surgery occur, opening the door to treatments, says at Stanford University in California.
It could also improve our understanding of narcolepsy, a condition in which people struggle to control when they sleep and wake, says at the Moss Rehabilitation Research Institute in Pennsylvania.
bioRxiv
