A new study showed that sleep deprivation increases the activity of inhibitory neurons in the hippocampus, an important area in the brain responsible for navigation and for processing and storing new memories.
Before exams, students sometimes pull all-nighters to study and prepare as best they can at the last minute. According to the study, this may actually be counterproductive and harmful and a good night’s rest would be more beneficial. Sleep deprivation increases the activity of inhibitory neurons in the hippocampus, an important brain area for navigating and processing, and storing new memories. This is the conclusion of a study just published in PNAS.
A window of time for the consolidation of memory
This study highlights the importance of sleep for the full mobilization of memory. Previous studies have shown that there is an ideal window of time, a few hours after learning when sleep allows memory to be fully consolidated. During this time, neuronal activity in the hippocampus must remain intact and RNA transcription and translation in neurons must function normally.
The researchers studied the interaction between sleep and wakefulness, hippocampal neuronal activity, and the phosphorylation induced by the activity of the ribosomal component S6 (organelles that translate mRNA into protein). This phosphorylation affects the mRNAs that are translated into proteins when neurons become more active. This regulation may be important in adapting to the neuron’s ever-changing metabolic requirements.
Hippocampal activity is disrupted
For the study, researchers gave mice a fear stimulus. When the mice were allowed to sleep freely after the stimulus, they found that S6 phosphorylation increased in a part of the hippocampus called the dentate gyrus, which is the first area where memories begin to form. However, when the mice were deprived of sleep, they observed that phosphorylation decreased throughout the hippocampus. This disrupted memories that the mice would otherwise have formed in response to the fear stimulus.
In diseases such as Alzheimer’s, where sleep disturbances are common, there may be a link between the physiological mechanism described in this study and memory loss,” says study co-author Sara Aton. But it could also be a neuronal protective function or an adaptive psychological response to stressful memories.”
This study’s conclusion that sleep loss disrupts the long-term storage of memories is no surprise as we already know that a poor night of sleep affects negatively our concentration and performance the following day.
What do you think about the results of the study? Please share your thoughts with our gilmore Health community in the comments area below!
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