PNAS Cognitive Processing Innovation Theory: In addition to neurons, astrocytes are also involved in memory and behavior

Textbooks we are familiar with generally describe the role of glial cells as follows: (1) providing scaffolding for neuronal growth; (2) Formation of an insulating layer (myelin sheath) around neurons, so that nerve impulses can be transmitted quickly; (3) Deliver nutrients to neurons and remove excessive neurotransmitters
between neurons.
And it is generally believed that mental activity is only related
to the nervous system composed of neurons.

Now, a team of scientists from the Krembill Brain Institute, part of the University Health Network in Toronto, and Duke University in Durham, North Carolina, have developed the first computer model
that predicts the role of cortical glial cells in cognition.
The paper was published today in
the prestigious journal Proceedings of the National Academy of Sciences (PNAS).

Dr Maurizio De Pittà, a scientist at the Krembir Institute for the Brain and first author of the study, said: "The role of neurons is well documented, but neurons are interspersed with glial cells, which are found near many synapses in the brain
.
We don't yet know how neurons and glia work together, or how glial dysfunction causes cognitive deficits
.
”

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

The paper presents the first theory
of the role that glia play in the brain's cognitive processes.
"The glial cell types we studied — called astrocytes — can change the activity of our brain circuits and influence the way we behave," says
Maurizio De Pittà.

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

"We know that astrocytes emit specific chemical signals, and we have shown that this signal can regulate different readings of working memory," says
Maurizio de Pittà.
"Uncovering the chemical interactions between neurons and astrocytes may be at the heart of working memory and also tell us what can go wrong when we have working memory deficiencies, which are often warning signs
of major brain disorders.
"

He added: "If we want to really understand the dysfunction of working memory, we need to consider the interaction
between glial cells and neurons.
"

The article also states:

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

• It is widely believed that different forms of working memory depend on different neuronal circuits; However, this study shows that the same glial circuits can encode various forms of working memory
  .
  

• The arrangement of astrocytes relative to neurons can control our working memory capacity, or how many things
  we can remember at the same time.
  

Currently, there is no effective technique to record glial activity
in the human brain.
The researchers hope to eventually create a high-fidelity model — the "digital twin" — of the brain's neuron-glial circuits, from genes to cells
.
Such models could help discover markers of neuron-glial interactions and improve the diagnosis and treatment of various brain disorders, such as Alzheimer's, Parkinson's and epilepsy
.

"With our new theory, we don't just look at the brain in black and white, that is, whether a given population of neurons is active or inactive
.
Instead, we are looking at the brain with color technology, gaining a deeper understanding of cellular communication by including glial cells and their signals," says
Maurizio De Pittà.
"This gives us a more comprehensive and realistic understanding
of the complexity of the brain.
"

As technology advances, Maurizio De Pittà and his team in Krembir will use their model to develop techniques to modify the activity of glial circuits to treat diseases
.
"Our ultimate goal is to study neuron-glial interactions to discover new therapeutic targets for brain diseases
.
"

New research paves way for innovative theory of cognitive processing