Sleep is a periodic suspension of consciousness which every vertebrate creature must enter regularly in order to survive. When asleep, the brain responds differently to stimuli than when awake.
Previously, scientists have confirmed the activeness of brain during sleep, but it is not clear about the changes happen in brain during sleep. Our brain runs on same neurons and requires same amount oxygen in both states – sleep and awake. But what makes these two states so different from one another?
In a study published in the journal PNAS, Rodolfo Llinás, a professor of Neuroscience at New York University School of Medicine and a Whitman Center Investigator at the Marine Biological Laboratory (MBL) in Woods Hole, and his colleagues, Choi, Yu and Lee announced that a specific calcium channel in brain plays a crucial role in healthy sleep – a key step toward understanding both normal and abnormal waking brain functions.
Llinás and his team studied the activity of calcium channel in mice. Calcium channels, selective gates in neuron walls, are integral in neuron firing, that make all parts of the brain communicate to one other. During sleep, the activity of calcium channel is increased, keeping a slow rhythm that is different from patterns found when awake.
Tweak in Calcium Channel in Mouse Brain
Based on the activities of calcium channel during sleep and awake, the scientists removed one type of calcium channel, Cav3.1 and observed how the absence of this calcium channel’s activity affected the brain function in mouse.
They found that calcium channel, Cav3.1, is the key player in normal sleep and it is significant in the generation of physiological unconsciousness. The mouse without this calcium channel took longer to fall asleep than normal mice and even if it did, it stayed asleep for much shorter periods
“They basically took cat naps,” says Rodolfo Llinás.
“Their brain activity was also abnormal, more like normal wakefulness than sleep. Most importantly, these mice never reached deep, slow-wave sleep. This means that we have discovered that Cav3.1 is the channel that ultimately supports deep sleep.”
The mice without calcium channel, Cav3.1 completely lack the ability to sleep deeply and they express a syndrome tantamount to psychiatric disorders in humans.
Llinás believes studying the activity of brain function during unconsciousness s key to understanding normal consciousness, as well as abnormal brain activity. The study reveals one of the key mechanisms of deep, slow-wave sleep and how one important calcium channel affects the overall function of the brain. [Hat Tip: Marine Biological Laboratory, Image via tek-tips.nethawk.net]