It is a known fact that the brain integrates or ‘consolidates’ new information learned throughout the day with prior knowledge and stores it for long-term use. However, a new study has revealed that breathing could be the driving ‘force’ that helps the brain to coordinate and consolidate memory during sleep.
The study published in the Proceedings of the National Academy of Sciences says that the breathing rhythms during sleep are linked to “slow spindles” brain waves in the hippocampus, part of the brain responsible for memory and learning.
According to the study, these brain waves occur during the non-rapid eye movement (NREM) phase of sleep.
The researchers at Northwestern University in the US said that though it was known that the slow spindles (a pattern of brain waves that occur during non-rapid eye movement sleep) played a role in memory, the ‘driver’ behind the process was not known.
These findings have important implications for conditions like sleep apnea, which disrupt breathing during sleep and are associated with poor memory consolidation, the researchers added.
"To strengthen memories, three special neural oscillations emerge and synchronise in the hippocampus during sleep, but they were thought to occur at random times," said study senior author Christina Zelano, a professor of neurology at Northwestern University.
"We discovered that these oscillations are coordinated by breathing rhythms," she said.
The activity in the hippocampus of six patients with epilepsy, entirely free of seizures, during nights were also analysed by the team.
The team found that slow spindle activity in the hippocampus occurred at specific points in the breathing cycle. The activity suggests that breathing is a critical rhythm for proper memory consolidation during sleep.
"Memory consolidation relies on the orchestration of brain waves during sleep, and we show that this process is closely timed to breathing," said author Andrew Sheriff, a postdoctoral researcher in Zelano's lab.
Sheriff also said that the study suggests that people with disrupted breathing during sleep should seek treatment.