A new study offers insights into the mechanisms that control pre-sleep behaviors and then the start of sleep in mice.
For people suffering from chronic difficulties initiating and maintaining sleep, adopting a regular behavioral pre-sleep routine was found to be more efficient in facilitating sleep than medication, yet the biological link between the pre-sleep phase and sleep initiation was until recently a mystery.
The findings, which appear in Current Biology, could have significant implications for insomniacs, who chronically struggle with falling and staying asleep.
Humans, as well as many other animals including mice, engage in routine behaviors prior to sleep initiation, including attending to personal hygiene and preparing a space in which to sleep. It has long been suggested that these pre-sleep behaviors promote tranquilization and de-arouse the brain, yet causal evidence was lacking.
In the newly published study, University of Michigan researchers characterized mice’s routine prior to sleeping and demonstrated that if mice are not able to engage in pre-sleep nesting behavior, it takes them longer to fall asleep and the quality of their sleep declines.
The researchers used new methods to tag neurons that were activated during the pre-sleep phase and subsequently modulate their activity. They successfully pinpointed neurons or brain cells in the lateral hypothalamus—which is a brain structure located in the forebrain and responsible for many behaviors including hunger, fear, and thirst—that not only controls pre-sleep nesting behavior, but also sleep intensity.
The findings could eventually lead to the development of alternative medication to treat sleep disturbances—other than currently available prescribed drugs which pose many health risks.
“A better understanding of the neuronal mechanism facilitating the natural transition from wakefulness to sleep could have large implications to numerous humans for which this transition is not a trivial one, for example for people suffering from insomnia,” says Ada Eban-Rothschild, assistant professor of psychology and neuroscience and the study’s senior author.
Source: University of Michigan