Researchers at Massachusetts General Hospital, led by Joshua Roffman, have found out how dopamine receptors support working memory, or working memory, in the brain. In particular, dopamine has been shown to redirect cognitive resources to maintain essential brain functions. The research is published in the journal Science Advances.
Dopamine, a neurotransmitter that mediates connections between neurons, is not only responsible for feelings of reward or pleasure, but also plays a role in shifting attention from one stage of cognitive activity to another. In other words, a lack of dopamine leads to a person's lethargy and inertia. In the prefrontal cortex, dopamine forms signaling pathways necessary for working memory to function. The neurotransmitter binds to the corresponding proteins - dopamine receptors, which transmit a signal into the neuron.
However, there is another network in the prefrontal cortex - the default one, which is not related to problem solving. When a person solves mathematical expressions, the default network must be silenced in order to activate other neural circuits. However, the mechanisms of this switch remained unknown.
To solve this problem, scientists examined the brains of 100 people who performed simple mental tasks to test working memory. Volunteers at the same time were scanned using positron emission tomography to analyze the synthesis of dopamine, its release by neurons and its connection with receptors. It turned out that the density of dopamine receptors in the prefrontal cortex was clearly related to how well the default network and the frontoparietal network, which is involved in the functioning of working memory, are disconnected.
The results could help researchers understand how interruptions in dopamine signaling affect the activity of cortical networks in schizophrenia and other neuropsychiatric disorders.
Working memory is a form of memory that is the ability to keep in mind the pieces of information needed to complete current tasks, such as solving a mathematical expression or understanding a complex problem.