Israeli researchers have located an area in laboratory rats' brains that controls their consciousness, a finding that might herald new treatments for various states of loss of consciousness, Xinhua reported.
Loss of response to painful stimuli and loss of consciousness are the most striking characteristics of surgical anaesthesia and anaesthesia-like states, such as concussion, reversible coma and syncope. These states also exhibit behavioral suppression, loss of muscle tone and depressed brain metabolism.
It has been widely presumed that this constellation of dramatic functional changes reflects widely distributed suppression of neuronal activity in the brain due to dispersed drug action or to global oxygen or nutrient starvation.
However, a Hebrew University of Jerusalem research team, led by Professor Marshall Devor, revealed "a radically different architecture," said the university in a statement on Monday.
"A small group of neurons near the base of the brain ... has executive control over the alert status of the entire cerebrum and spinal cord, and can generate loss of pain sensation, postural collapse and loss of consciousness through specific neural circuitry," said the statement.
The conclusion is reached from the observation that microinjection of tiny quantities of certain anesthetic drugs into this newly discovered "center of consciousness" in laboratory rats induced a profound suppressive effect on the activity of the cerebral cortex, added the statement.
While noting that it is not certain that these results will translate reliably from rats to man, the researchers predicted that "if they do, there are at least two implications of considerable interest."
The first one is that this knowledge could help improve treatments for disorders of consciousness and its loss, such as insomnia, excessive sleepiness and even coma.
"Perhaps by direct electrical stimulation of the cells in question, it might prove possible to arouse a patient from coma," said the statement.
The second is that the discovery can be expected to introduce an understanding of the actual wiring diagram that permits a biological machine, the brain, to be conscious.