This is another case for the brain being more flexible than originally thought.
A Children’s National Health System study, in collaboration with research groups at the University of California, San Francisco and University of California, Santa Cruz, has found unexpected flexibility in the rules governing neuronal circuit formation in the brain.
Neuronal connections responsible for processing vision in the brain are often organized in what are known as topographic maps, says Jason W. Triplett, PhD, Principal Investigator, Neuroscience, for the Children's Research Institute and co-author of the study published in Neuron.
For years, it was widely known that molecular cues and neuronal activity play critical roles in map formation, but researchers were uncertain how these forces interact. In this new research, investigators found that the formation of the maps does not adhere to a rigid wiring diagram, and instead there appears to be a “push-pull” interaction between molecules and activity.
The formation of a proper pattern of neuronal circuits during development is critical for the normal function of the brain, and while the impact of the study isn’t immediately known, Dr. Triplett says it could have broad implications.
“These findings not only resolve the issue of the relative roles of molecular cues and activity in the establishment of topography, but also show a novel stochasticity in this process,” Dr.Triplett and colleagues wrote in the study. The term stochastic refers to unpredictable nature of systems, due to the influence of variable randomness. Ultimately, this means that visual projections may be organized differently from individual to individual.
Understanding the forces driving this is critical for developing medications to compensate for alterations in connectivity associated with disease states, such as autism and intellectual disability, according to Dr. Triplett.
“This is a significant finding because it shows broad differences from what was previously believed and scientists should rethink how we interpret current models of neuronal connection development, particularly in the visual system,” Dr. Triplett says.
Contact: Lauren Lytle at 202-476-4500.###