Brain self-organization is the key to development

Summary: A new study reveals that the cerebral cortex can self-organize during development, transforming unorganized inputs into highly structured patterns of activity. This self-organization is guided by mathematical rules similar to those found in other natural systems. Disruptions in these patterns could impact sensory perception and contribute to neurodevelopmental disorders like autism.

Highlights:

• The cortex can self-organize neuronal activity during development.
• This self-organization is guided by mathematical rules found in nature.
• Disruptions in these patterns can contribute to neurodevelopmental disorders.

Source: University of Minnesota

Published in Natural communicationsan international collaboration between researchers at the University of Minnesota and the Frankfurt Institute for Advanced Study studied how highly organized patterns of neuronal activity emerge during development.

They found that the cerebral cortex can transform unorganized input into highly organized patterns of activity, demonstrating self-organization.

“What makes this transformation so important is that it appears to occur entirely within the cortex itself, indicating that the brain is capable of organizing its own functions during development,” said Gordon Smith , PhD, assistant professor in the Faculty of Medicine at the University of Manitoba. .

“This suggests that any disruption of these small-scale interactions can dramatically alter brain function, which can impact sensory perception and possibly contribute to neurodevelopmental disorders like autism.”

In a self-organizing system, small-scale interactions combine to generate large-scale organization. By closely combining theory and experiment, the research team was able to show that mathematical rules similar to those that govern patterns in a wide range of living and non-living systems, such as the spots on some fish and the spacing of dunes sand, also guide brain development.

“Our results suggest that patterns of neuronal activity in the early cortex arise dynamically through feedback loops that involve a balance between local activation and lateral suppression, confirming a decades-old theoretical hypothesis of brain development,” said Matthias Kaschube, PhD, professor at the University of Frankfurt. Institute for Advanced Studies and co-investigator of the study.

The research team used optical tools recently developed at the University of Manitoba to directly demonstrate how the large-scale structure of developing brain networks emerges from the networks themselves, rather than being imprinted from a external source.

“Using cutting-edge optical techniques, these experiments allowed us to test a long-standing scientific theory and show that the brain organizes its own activity during early development,” said Dr. Smith, who is also a member of the medical discovery team. on optical imaging and brain science.

Ongoing research is exploring how alterations in these patterns of self-organized neural activity early in development impact sensory perception later in development.

Funding: Funding was provided by the National Eye Institute (grant R01EY030893-01), the Whitehall Foundation (2018-05-57), the National Science Foundation (IIS-2011542) and the Federal Department of Education and Research ( BMBF 01GQ2002).

About this neurodevelopment research news

Author: Alexandra Smith
Source: University of Minnesota
Contact: Alexandra Smith – University of Minnesota
Picture: Image is credited to Neuroscience News

Original research: Free access.
“Self-organization of modular activity in immature cortical networks” by Gordon Smith et al. Natural communications

Abstract

Self-organization of modular activity in immature cortical networks

During development, cortical activity is organized into distributed modular patterns that are a precursor to the mature functional columnar architecture.

Theoretically, such structured neuronal activity can emerge dynamically from local synaptic interactions through a recurrent network with effective local excitation with lateral inhibition (LE/LI) connectivity.

Using simultaneous wide-field calcium imaging and optogenetics in the juvenile ferret cortex before eye opening, we directly test several critical predictions of an LE/LI mechanism. We show that cortical networks transform uniform stimuli into various modular patterns exhibiting a characteristic spatial wavelength.

Furthermore, structured optogenetic stimulation matching this wavelength selectively biases evoked activity patterns, while stimulation with varying wavelengths shifts activity toward this characteristic wavelength, revealing a trade-off dynamics between the input command and the intrinsic tendency of the network to organize activity.

Furthermore, the structure of early spontaneous cortical activity – which is reflected in developing representations of visual orientation – strongly overlaps with that of uniform opto-evoked activity, suggesting a common underlying mechanism as the basis for the formation of ordered columnar maps underlying sensory representations in the brain.