PNAS: Staying up late will increase inhibitory neuron activity and destroy human memory

In today’s society, staying up late has become the “new normal” for many young people.

We all know that staying up late is very harmful.

On August 5, 2021, researchers from the University of Michigan in the United States published a research paper titled Sleep loss drives acetylcholine- and somatostatin interneuron-mediated gating of hippocampal activity to inhibit memory consolidation in the Proceedings of the National Academy of Sciences (PNAS)

The study found that when staying up late leads to insufficient sleep, the activity of inhibitory neurons in the hippocampus that navigate and process and store new memories in the brain increases

Previous studies have shown that after a few hours of learning, there is a sensitive time window during which you must sleep to fully consolidate the memories generated by previous learning.

First, the research team studied the interaction between sleep and wakefulness, hippocampal neuronal activity, and activity-driven phosphorylation of ribosomal S6 protein, which is a component of ribosomes responsible for protein translation

The research team gave the mice a fear stimulus.

But when these mice were deprived of sleep, their phosphorylation levels throughout the hippocampus decreased

Next, the research team tried to investigate whether this activity-driven reduction of ribosomal S6 protein phosphorylation would have a similar effect on all neurons after lack of sleep

The research team observed that after sleep deprivation, the abundance of one type of RNA transcripts increased significantly, and these transcripts are known to be exclusively present in interneurons that express the neuropeptide somatostatin and the inhibitory neurotransmitter GABA

Then, the research team conducted further studies on mice, and they found that when mimicking this inhibitory gating mechanism in free-sleeping mice, it can disrupt hippocampal activity and memory consolidation

This research opens new doors for further research on how manipulating the relative balance between excitatory and inhibitory neuronal activity affects memory and sleep

This research also reminds us that proper rest or sleep after studying for a period of time can better consolidate memory.

Original source:

James Delorme, et al.