The mystery story ofsleepare get down to unravel thanks to a unexampled report that unwrap how the brain transform the day ’s result into full encode memory while we kip . appear in the journalScience , the fresh research designate that the fine - tuning of these memory occurs during periods of extremely low brainwave action , when the vast majority of cortical neurons switch off in guild to allow only those involved in creating a specific memory to do their piece of work .
scientist have screw for decades that during sleep , neurons across the pallium oscillate between outburst of activity and periods of silence . Because the dynamic stage is straightaway forgo by a billow of activity in thehippocampus – the part of the brain that processes memory – it has long been take that this oscillation somehow serves to encode recent effect into fixed memories .
During the silent phase of the cycle , nerve cell across the pallium synchronize to the slowest type of brainwave , have sex as delta wave , contribute scientist to consider that the nerve cell are simply repose during this period . However , the novel study reveals for the first sentence that not all of the cortical neuron in reality go to sleep , and that a very small bit really remain dynamic and group together to form neural connections that make specificmemories .
The study authors groom rats to do a spacial retention task , and record their hippocampal and cortical bodily function both during the task and during the first two hours of sleep . They discovered that while the gnawer weresnoozing , their hippocampi spontaneously replicate the natural process formula it had expose during the memory task , indicating that it was replay the memory of the event .
As have a bun in the oven , this caused a stiletto heel of activity across the cortex , watch by delta wave and the corresponding neuronal silence . Yet each time this materialise , a small nonage of cortical neurons stay combat-ready while the rest sleep . By abide by this process , the team attain that the activeness figure within the hippocampus in reality predicted which cortical neuron would remain active , allowing them to observe in genuine - time as short - term retentivity in the genus Hippocampus were register as stable memories in the cortex .
To confirm their finding , the researchers later artificially make the cortices of the sleeping rats , causing the wrong nerve cell to remain active during the delta phase , and launch that this prevented the fauna from being able to complete the spatial memory task the next day .
Above all , this discovery is pregnant as it radically alters our understanding of delta waves and their determination : rather than simply sending the brain to sleep , these wafture survive in fiat to isolate the specific neurons that are needed to work a remembering , suppressing all the others so that those selected can get to oeuvre .
