A good night’s sleep, uninterrupted by noises, depends on the rhythm of the activity of neurons in the brain, according to scientists from the US in the journal Current Biology.
Most of us have wondered at least once why some people can sleep anyway, while others are awakened by every night murmur. In their latest work, Jeffrey Ellenbogen’s group at Harvard Medical School showed that the lucky ones had a different rhythm of neuron activity in the brain.
We found, when studying brain waves during sleep, that the more so-called Your brain produces sleep spindles, the more you sleep, despite the sounds around you, says the lead author of the study. Sleep spindles are a type of fast waves emitted by the brain during deep sleep, the so-called not REM or NREM. As you sleep, your brain waves become slow and rhythmic and orderly. Sleep spindles are shown on an electroencephalogram (EEG) as high frequency short waves.
These waves are generated by the brain’s hypothalamus, which is a region that processes almost all types of sensory information (except for smell). According to the researchers, the hypothalamus prevents auditory information from reaching the parts of the brain that perceive it and trigger a response during sleep. The authors of the study showed that sleep spindles act as a stimulus blocker – the more there are, the more stable sleep is, even in noisy environments.
In order to study brain activity during sleep, scientists asked project participants to spend three nights in the laboratory – the first night was not disturbed by the subjects’ sleep – it was quiet, the second and third nights were noisy. Various sounds were played for participants – including telephone ringing, conversation sounds and mechanical sounds typical of a hospital.
As the authors of the study argue, the effect of the sleep spindles was so evident that their significance was discovered on the very first night. Scientists hope to find ways to enhance sleep spindles by behavioral methods, drugs or other safe and effective methods.
At the end of their work, the authors advise people who cannot fall asleep without the radio or TV turned on to set timers to turn them off. Research results clearly show that this type of noise disturbs sleep, whether the sleeper is aware of it or not. (PAP)