It’s well known that when we go to sleep, our brains begin “saving” and organizing memories that occurred during the day. To save these memories, synchronized regions in the brain coordinate to share information between neural areas. Science does not yet understand the mechanisms behind this synchronization of areas. It has previously been assumed that the mechanisms occurred in correlated brain activity patterns, but a recent study suggests otherwise. Instead, scientists actually say breathing functions as a sort of pacemaker, synchronizing the regions of the brain.
Breathing has been shown to have significant physiological effects on the body’s autonomous nervous system, and it is capable of attuning many cognitive functions, including perception, attention, and thought structure. Despite the widely understood positive regulatory effects of breathing, it is still unclear how it influences cognitive function and the brain.
For their study, researchers from Loyola Marymount University gathered in vivo electrophysiological recordings in mice across thousands of limbic system neurons. Through their many collected recordings, they found that respiration coordinates and entrains neuronal activity in each brain region they observed: the hippocampus, medial prefrontal, and visual cortex, thalamus, amygdala, and nucleus accumbens. This phenomenon occurs by regulating circuit excitability separately from the olfactory function.
“Thus, we were able to prove the existence of a novel non-olfactory, intracerebral, mechanism that accounts for the entrainment of distributed circuits by breathing, which we termed ‘respiratory corollary discharge’,” says Karalis, a research fellow at the Friedrich Miescher Institute for Biomedical Research in Basel, in a statement.
Their results, researchers say, contradict the previously held theory that olfaction plays a role in breath-modulated brain activity. “Our findings identify the existence of a previously unknown link between respiratory and limbic circuits and are a departure from the standard belief that breathing modulates brain activity via the nose-olfactory route,” adds Sirota.
This link serves as a connector for essential memory creating sleep-related activity in the identified brain regions, as well as enabling co-modulation of the cortico-hippocampal circuits synchronous dynamics.
Researchers believe that results found in this study mark significant advancement in the development of new mechanistic theories understanding the critical role of respiratory rhythm in synchronizing dispersed brain regions for the function of memory consolidation.
Future research will be required to further understand the modulating function of breathing rhythms. Researchers believe that such studies may reveal functional sub-networks at work in particular behaviors involved in the process. Additionally, advancing knowledge of respiratory modulation may help explain the role of breathing in meditation and similar spiritual and rehabilitation practices, as well as regulating patients’ emotional outbursts.
This study is published in Nature Communications.
Article written by Anna Landry