Electric fields help guide neural activity, even from moment to moment

A new study reveals that electric fields significantly influence neural activity and stability, even on a moment-to-moment basis. Published in Cerebral Cortex, the findings, led by researchers at MIT, suggest that the brain's electric fields act as crucial control signals for its overall function. Lead author Earl K. Miller, Picower Professor of Neuroscience, explains that the brain is a "rollicking sea of electrical influences," traditionally studied for its spiking and synaptic connections.

However, this study demonstrates that electric fields, known as "ephaptic coupling," actively help organize neural activity and coordinate the firing of individual neurons. The researchers analyzed data from animals performing a working memory task, observing that neural activity varied considerably between trials. By calculating the local electric fields at each moment, they found that these fields, captured through local field potentials, strongly influenced neural activity.

The strength of this influence was proportional to the variability in local field power, suggesting that electric fields serve as control parameters for brain function. This discovery opens possibilities for therapeutic interventions that could potentially improve brain function in diseases by manipulating electric fields at the mesoscale level.