New research paves the way for an innovative theory of cognitive processing

A team of scientists from the Krembil Brain Institute, part of the University Health Network in Toronto, and Duke University in Durham, North Carolina, have developed the first computer model predicting the role of cortical glial cells in cognition.

The article was published today in the journal Proceedings of the National Academy of Sciences (PNAS).

“The role of neurons is well documented, but neurons are interspersed with glial cells and many synapses in the brain have glial cells nearby,” says Dr. Maurizio De Pittà, scientist at the Krembil Brain Institute and first author of the study. . “We currently don’t understand how neurons and glia work together, or how glial dysfunction contributes to cognitive deficits.”

Glial cells are abundant throughout the brain and play several important roles. These cells have long been thought of as passive spectators – physically supporting neurons and synapses, delivering nutrients to neurons, and removing toxins and wastes. However, scientists have recently discovered that glia interact with neurons in a way similar to how neurons communicate with each other through chemical signals.

This article presents the first theory of the role played by glia in cognitive processing in the brain. “The type of glial cells we study – known as astrocytes – can alter the activity of our brain circuits and influence our behavior,” says Dr De Pittà.

The study looked at the role of astrocytes in working memory, which is the ability to store information for ongoing tasks, such as following a movie script or counting to ten.

“We know that astrocytes release specialized chemical signals and we have shown that this signaling can mediate different readings of working memory,” says Dr. De Pittà. “Revealing that chemical interactions between neurons and astrocytes could be at the heart of working memory also tells us what could go wrong when we have working memory deficits, which are often early warning signs of trouble. major brains.”

He adds, “If we really want to understand working memory dysfunction, we need to consider the interaction between glial cells and neurons.

Also noted in the article:

• Like radio systems, synapses have traditionally been thought to transmit on a single frequency band. Taking astrocytes into account, we now know that there can be multiple frequency bands.

• Different forms of working memory are generally thought to rely on a variety of circuitry; however, this study shows that the same neural-glial circuits could code for various forms of working memory.

• The way astrocytes are arranged in relation to neurons could control our working memory capacity or the number of things we can keep in mind simultaneously.

Currently, there is no effective technique to record glial activity in the human brain. The researchers eventually hope to create a high-fidelity model – a “digital twin” – of the neuron-glia circuitry of the brain, from genes to cells. Such a model can help discover markers of neuron-glia interactions and improve the diagnosis and treatment of various brain diseases, such as Alzheimer’s disease, Parkinson’s disease and epilepsy.

“With our new theory, we are not just looking at the brain in black and white, that is, whether given populations of neurons are active or inactive. Rather, we are viewing the brain in technicolor, gaining a deeper understanding depth of cellular communication including glia and their signalling,” explains Dr. De Pittà. “This gives us a much more complete and realistic picture of the complexity of the brain.”

As technology advances, De Pittà and his Krembil team will use their models to develop techniques to alter neuron-glial circuit activity to treat disease. “Our ultimate goal is to study neuron-glia interactions to discover new therapeutic targets for brain disorders.”

Sharon D. Cole