Researchers have devised a new theory about how the brain differentiates between relevant and irrelevant information, based on a computational model.

Published in the journal Nature Communications, the study by New York University researchers focused on inhibitory neurons, which are responsible for neurological responses to incoming stimuli by suppressing other neurons, while balancing the excitatory neurons.

“It is critical to our everyday life that our brain processes the most important information out of everything presented to us,” said senior author Xiao-Jing Wang, global professor of neural science at NYU and NYU Shanghai, in a press release. “Within an extremely complicated neural circuit in the brain, there must be a gating mechanism to route relevant information to the right place at the right time.”

In the study, the researchers devised a model that challenges the previously suggested role of the inhibitory neurons, and showcased a more complicated one.

“Our model uses a fundamental element of the brain circuit, involving multiple types of inhibitory neurons, to achieve this goal,” Wang explained. “Our computational model shows that inhibitory neurons can enable a neural circuit to gate in specific pathways of information while filtering out the rest.”

A specific subtype of inhibitory neurons targets the excitatory neurons’ dendrites (parts where inputs from other neurons are located) and is labeled by the biological marker, somatostatin. Under the study, the authors proposed that these neurons are not just responsible for the overall inputs to a neuron, but also the inputs from individual pathways like those responsible for sight and smell.

“This was thought to be difficult because the connections from inhibitory neurons to excitatory neurons appeared dense and unstructured,” Guangyu Robert Yang, a doctoral candidate in Wang's lab, said in the statement. “Thus a surprising finding from our study is that the precision required for pathway-specific gating can be realized by inhibitory neurons.”