Source: University of California – San Diego
Summary: Researchers have uncovered how the oxygen levels in different hemispheres of the brain connect to share the signals even when the body is in resting state.
Researchers have already known that brain areas with similar functions in different hemispheres of the brain connect to share the signals, even when the body is in resting state. But they haven’t known how this “resting-state connectivity” happens. Researchers in the Neurophysics Laboratory at the University of California San Diego with the help of an advanced form of optical microscopy have studied micro changes in the blood vessels across brain’s cortex of a mouse. They revealed a series of interactions which uncovered how oxygen levels correlate over large distances even those in different brain hemispheres by using fMRI (functional Magnetic Resonance Imaging – a tool used to study the involvement of different brain regions in human behavior). The findings of this study are published in the journal Neuron.
During their study researchers observed the slow variation in amplitude of high-frequency electrical signals in the resting brain linked with attention span. This slow variation (period of 10 seconds) corresponds with slow vibrations in the muscles surrounding arterioles in the brain. The rhythmical contractions and relaxations of the muscles bring about changes in the diameter of the arterioles and modulate the oxygen levels in neighboring brain tissues. The researchers say that their results will have a significant impact on human health and medicine applications which also include high-resolution imaging methods to study connections in the brain.
Prof. David Kleinfeld said, “One impact of our results is to use MRI and directly study fluctuations in the diameter of blood vessels across the brain”,
Mateo said, “Our next question is to ask how blood vessels participate on the regenerative effect of sleep”, “We hope that applying our arsenal of optical and genetically engineered tools will advance our understanding of this fascinating subject.”
More Information: Celine Mateo et al. “Entrainment of Arteriole Vasomotor Fluctuations by Neural Activity Is a Basis of Blood-Oxygenation-Level-Dependent “Resting-State” Connectivity” Neuron (2017). DOI: 10.1016/j.neuron.2017.10.012