In what could lead to new treatment for sleep disorders, including insomnia, researchers have developed designer genes to remotely control neurons in a part of the brain responsible for deep sleep.
Half of all of the brain's sleep-promoting activity originates from the parafacial zone (PZ) in the brainstem, the findings showed. This is only the second "sleep node" identified in the mammalian brain whose activity appears to be both necessary and sufficient to produce deep sleep.
The brainstem is a primordial part of the brain that regulates basic functions necessary for survival, such as breathing, blood pressure, heart rate and body temperature.
The researchers found that a specific type of neuron in the PZ that makes the neurotransmitter gamma-aminobutyric acid (GABA) is responsible for deep sleep.
They used a set of innovative tools to precisely control these neurons remotely, in essence giving them the ability to turn the neurons on and off at will.
"We are at a truly transformative point in neuroscience where the use of designer genes gives us unprecedented ability to control the brain," said study co-author Caroline Bass, an assistant professor at University at Buffalo School of Medicine and Biomedical Sciences.
"These new molecular approaches allow unprecedented control over brain function at the cellular level," said co-researcher Christelle Ancelet from Harvard School of Medicine in the US.
To get the precision required for these experiments, the researchers introduced a virus into the PZ that expressed a "designer" receptor on GABA neurons only but did not otherwise alter brain function.
"When we turned on the GABA neurons in the PZ, the animals quickly fell into a deep sleep without the use of sedatives or sleep aids," Patrick Fuller, an assistant professor at Harvard School of Medicine explained.
The study appeared online in the journal Nature Neuroscience.
