However, the sleep-restricted rats that had to rely on memory to find the goal showed no increased neurogenesis, unlike their rested counterparts. This means that lack of sleep undoes the cell rejuvenation benefit that would normally come from the task, the researchers noted.
Sleep restriction prompts use of a secondary strategy
On the other hand, the sleep-restricted rats that were required to locate the platform using visual and odor cues did better on the task than their rested counterparts. This was an unexpected finding.
Hairston et al. believe it is because the rested group tried to rely on memory to find the platform, generally a better strategy to reach a goal you have reached before. But in this case, where the researchers moved the goal every fourth trial, using the visual and odor cues was a better strategy. It appears that the sleep-restricted rats changed their strategy to compensate for their lack of sleep ?and it worked.
"The sleep-restricted rats in this group actually did better because the lack of sleep interfered with their ability to memorize the maze -- forcing them to rely on easily accessible cues," Hairston said.
Researchers point to practical implications for the overtiredOverall, the study underlined that learning depends upon two things: exposure to novel material and getting a good night's sleep, Hairston said.
Learning new things, at least in the case of spatial memory, quite literally keeps your brain young by ensuring a better survival rate for new brain cells in the hippocampus. However, not getting enough sleep eliminates the potential benefit of new learning on the hippocampus by suppressing neurogenesis. "Mild, chronic sleep restriction may have long-term deleterious effects on neural functioning," according to the paper.
On the other hand, that sleep-deprived rats did better on a
Source:American Physiological Society