Scientists have discovered a new "sleep node" in the brain that shows just how important sleep really is, as well as could potentially help in the treatment of sleep disorders.
This sleep node is one of only two identified in the mammalian brain whose activity appears to be both necessary and sufficient in producing deep sleep.
Discovered by researchers at Harvard School of Medicine and the University at Buffalo School of Medicine and Biomedical Sciences, the sleep node in question is a specific type of neuron found in the parafacial zone (PZ) in the brainstem.
This part of the brainstem is crucial for survival, as it regulates breathing, blood pressure, heart rate and body temperature. But this new study also shows that it's involved in promoting sleep activity as well.
"The close association of a sleep center with other regions that are critical for life highlights the evolutionary importance of sleep in the brain," co-author Caroline E. Bass said in a statement.
The researchers pinpointed a neuron in the PZ, which makes the neurotransmitter gamma-aminobutyric acid (GABA), is responsible for deep sleep. Using a set of innovative tools they were able to precisely control these neurons remotely, essentially turning them on and off at will. This approach ensures that they are only turning on the brain regions they want to without stimulating other areas that would hinder results - like with traditional electrical stimulation.
"It was a sledgehammer approach, when what we needed was a scalpel," explained fellow researcher Christelle Ancelet.
"To get the precision required for these experiments, we introduced a virus into the PZ that expressed a 'designer' receptor on GABA neurons only but didn't otherwise alter brain function," explained Patrick Fuller, assistant professor at Harvard and senior author on the paper. "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."
Though researchers need to further study the influence of these neurons on other parts of the brain associated with sleep and wakefulness, they believe the findings could result in new medications for treating sleep disorders like insomnia.
The findings were published in the journal Nature Neuroscience.