Summary: A new study in rodents suggests a direct link between breathing patterns and changes in brain activity, with implications for understanding how controlled breathing may influence emotion and mental states.
Source: Penn State
Mental health clinicians and meditation practitioners have long argued that intentional breathing can calm the mind, but the exact brain mechanisms behind this effect remain unclear.
Researchers at the Penn State College of Engineering used simultaneous functional magnetic resonance imaging (fMRI) and electrophysiology to investigate how respiration relates to neural activity in rats. Their results, available ahead of print in eLife, point toward a neural component of respiration that affects resting-state fMRI signals.
“There are roughly a million papers published on fMRI—a non-invasive imaging technique that allows researchers to examine brain activity in real time,” said Nanyin Zhang, founding director of the Penn State Center for Neurotechnology in Mental Health Research and professor of biomedical engineering. “Imaging researchers used to treat respiration as a non-neural physiological artifact, like heartbeat or motion. Our study introduces the idea that respiration itself can modulate neural activity and thus influence the fMRI signal.”
By scanning anesthetized rats in a resting state, the team identified a network of brain regions whose activity correlated with the animals’ breathing rhythms. To separate true neural effects from physiological artifacts—such as motion and carbon dioxide fluctuations—the researchers combined fMRI with direct electrical recordings of neuronal activity (electrophysiology).
That multimodal approach allowed the scientists to pinpoint breathing-related neural dynamics in the anterior cingulate cortex, a central region involved in emotional processing and regulation. They found that slow variations in respiration were phase-locked with changes in gamma-band power recorded in that cortical area, indicating a robust link between breathing rhythm and local neural activity.
Importantly, the study distinguishes respiration-related neural effects from common non-neural fMRI artifacts. The researchers observed a characteristic resting-state fMRI network tied to slow respiratory variations, and they showed this network was mediated by gamma-band neural activity. When the researchers suppressed brain-wide neural signaling to an isoelectric state—while maintaining respiration—the respiration-associated network disappeared, further supporting the conclusion that neural activity is necessary for the observed fMRI pattern.
“Breathing is a need common to almost all living animals,” Zhang said. “We know that a brainstem circuit controls basic respiratory rhythm, but until now we lacked a clear picture of how breathing influences other brain regions. Our experiments provide direct evidence that respiration can drive neural activity beyond the brainstem.”
The results shed light on the physiological basis of resting-state fMRI signals and suggest a pathway by which breathing may shape emotional state. The correlation between breathing rhythm and neural activity in the cingulate cortex, a region implicated in emotion and attention, supports the idea that respiration can influence mood and cognitive function.
“When people feel anxious, their breathing often becomes faster; conversely, slowing and deepening the breath is a common strategy to reduce anxiety,” Zhang explained. “We also tend to hold our breath when concentrating. Those everyday observations imply a link between breathing and brain function, and our data provide a mechanistic basis for that link.”
The researchers propose that extending these simultaneous recording techniques to humans could clarify how controlled, slow breathing practices used in meditation and therapy alter neural activity and reduce stress. Future studies may examine human subjects during meditation or breath-control exercises to map how intentional respiration changes brain networks associated with emotion and self-regulation.
“Our current understanding of how breathing affects the brain is still quite limited,” Zhang said. “If researchers can replicate these multimodal findings in humans, we may be able to explain the neural mechanisms underlying breathing-based interventions for anxiety and stress.”
About this neuroscience research news
Author: Mariah Chuprinski
Source: Penn State
Contact: Mariah Chuprinski – Penn State
Image: The image is in the public domain
Original Research: Open access. “Neural underpinning of a respiration-associated resting-state fMRI network” by Wenyu Tu et al., eLife
Abstract
Neural underpinning of a respiration-associated resting-state fMRI network
Respiration can induce motion and CO2 fluctuations during resting-state fMRI (rsfMRI) scans, creating non-neural artifacts in rsfMRI signals. At the same time, as a fundamental physiological process, respiration may directly drive changes in neural activity and thereby modulate rsfMRI measurements. This neural component of the respiration–fMRI relationship has been largely unexplored.
To investigate this issue, the study simultaneously recorded electrophysiology, rsfMRI, and respiration signals in rats. The data show that slow variations in respiration are phase-locked with gamma-band power in electrophysiological recordings from the anterior cingulate cortex, indicating a direct association between breathing rhythm and neural activity.
Moreover, slow respiratory variations correspond to a specific rsfMRI network that is mediated by gamma-band neural activity. When brain-wide neural activity was silenced to an isoelectric state while respiration continued, the respiration-related rsfMRI network vanished, confirming that neural activity is required for this network to appear. Together, these results identify a respiration-associated brain network underpinned by neural activity—a novel component of the respiration–rsfMRI relationship distinct from standard respiration-related artifacts.
This work opens a new avenue for investigating interactions among respiration, neural activity, and resting-state brain networks in both health and disease, and suggests that breathing patterns could play a mechanistic role in modulating brain function relevant to emotion and attention.