Are we ever able to recollect or even realize that exact defining moment when we drop off to sleep, and how and why?
Sleep and dreams have boggled scientific minds for ages, and strangely very little is really known about these everyday phenomena.
In a recent study, researchers from the University of Maryland School of Medicine (UM SOM) were able to go in-depth and pinpoint some significant neural mechanisms that take place in the brain that seem to be responsible for inducing sleep.
A neural pathway of sorts has been detected that appears to help with the transition from wakefulness to sleep and vice versa. It behaves like an on-off button. Findings on this subject could greatly contribute toward treatments for sleep-deprived conditions such as jet lag and insomnia.
The study particularly focuses on a certain region of the brain known as the suprachiasmatic nucleus, located in the hypothalamus. This area refers to a small group of brain cells responsible for the regulation of the brain's internal clock or circadian cycles.
Circadian rhythms or cycles are approximately a 24-hour biological cycle (day to night) that is present in humans, animals and plants. All living organisms have a circadian cycle, which enables one to function on a day-to-day basis in terms of eating, sleeping and other activities.
The study conducted by Maryland scientists were performed on mice. It's important to note that the mice's sleep cycle is opposite to that of humans', wherein they sleep during the day and are up and about at night.
The team analyzed a group of neuronal ion channels or BK potassium channels (proteins that allow ions or electrically charged atoms to move across a cell) within the suprachiasmatic nuclei of several mice. These BK potassium channels were found to be particularly active in the suprachiasmatic nucleus. In mice, however, these BK channels were observed to be active at night since that's when they tend to be in their wakeful state.
"We knew that BK channels were widely important throughout the body. But now we have strong evidence that they are specifically and intrinsically involved in the wake-sleep cycle. That's really exciting." said Andrea Meredith, Associate Professor of Physiology at UM SOM.
The new paper reveals that it's not really about the number of channels as previously suggested by other studies, but more so about the channels being active or inactive at certain times of the day and night. This is possibly the first study that reveals how inactivation of the BK channel is pivotal for encoding the circadian rhythm in the brain.
The findings were published in the journal Nature Communications.