Sleep seems simple enough, a state of rest and restoration that almost every vertebrate creature must enter regularly in order to survive. However, the brain responds differently to stimuli when asleep than when awake, and it is not clear what brain changes happen during sleep. Now, researchers from the New York University School of Medicine have started to investigate the difference between these two brain states including the neural networks used, oxygen requirements and so on. In a new study they have identified a specific calcium channel which plays a crucial role in healthy sleep, a key step toward their goal of understanding both normal and abnormal waking brain functions. The opensource study is published in the journal Proceedings of the National Academy of Sciences.
Previous studies show that calcium channels, selective gates in neuron walls, are integral in neuron firing, ensuring that all parts of the brain keep talking to one other. But during sleep, calcium channel activity is increased, keeping a slow rhythm that is different from patterns found during wakefulness. To tackle the broad question of sleep the current study focused on one crucial part of the puzzle in a mouse model. The researchers removed one type of calcium channel, Cav3.1, and looked at how the absence of that channel’s activity affected mouse brain function.
The data findings showed that this calcium channel turns is also a key player in normal sleep. The mice without working Cav3.1 calcium channels took longer to fall asleep than normal mice, and stayed asleep for much shorter periods. The results showed that they basically took cat naps. Their brain activity was also abnormal, more like normal wakefulness than sleep. Most importantly, state the team, these mice never reached deep, slow-wave sleep. This means that Cav3.1 is the channel that ultimately supports deep sleep.
The team note that because these mice completely lack the ability to sleep deeply, they eventually express a syndrome similar to psychiatric disorders in humans. They go on to add that studying how the brain functions during unconsciousness is key to understanding normal consciousness, as well as abnormal brain activity. The researchers surmise that the current study begins to uncover one of the key mechanisms of normal sleep, as well as the role for one important calcium channel in overall brain function.