Brain Structure Mapping Alone Fails to Capture Its Functionality

Is it possible to fully comprehend brain function if we can accurately map its structures? Researchers aim to develop a wiring diagram, or connectome, of our neural pathways, yet the task of unveiling the brain’s mysteries is proving to be complex.

The Connectome serves as a roadmap for nerve signal pathways, but Sophie Dovari from Princeton University and her team have found notable gaps in these pathways.

Researchers analyzed the connectome of the nematode worm, Caenorhabditis elegans, and compared it to recorded neural signals. They accomplished this by stimulating each neuron and observing how signals flowed through the connectome. This method is feasible with nematodes due to their relatively simple nervous system, composed of roughly 300 neurons.

By viewing these two datasets as mathematical networks, researchers can ascertain whether closely connected groups of neurons manifest a high frequency of signal exchanges. They uncovered that this correlation is not always evident.

Dvali notes instances of substantial connection density and overlapping signal exchanges, like how worms eat or the groups of neurons that correspond well. However, even in cases where they appeared significantly connected, a gap remained in understanding their respective functionalities across both networks. Overall, these findings suggest that the biological connectome is insufficient to predict all neural behaviors.

Team member Andrew Leifer, also from Princeton University, points out that signals do not always follow the shortest paths between neurons; some may communicate beyond their direct connections. “While we typically leverage connectomes for research, the multitude of useful connections calls for deeper comprehension,” he explains.

According to Albert Laslo Barabasi at Northeastern University, Massachusetts, criticism surrounding connectomics often revolves around its inability to provide action-oriented insights from structural data. This new paper seeks to address that challenge.

Looking forward, researchers aim to delve deeper into how signals disseminate through the connectome when multiple neurons are activated simultaneously, with aspirations to study more complex organisms, such as fruit fly larvae, recognized for their intricate neural networks. “We are on the verge of a revolution in brain mapping,” Barabasi concludes.