Cognitive Flexibility: How the Brain Learns New Rules for Navigating a Changing World

summary: In everyday life, our brain uses the prefrontal cortex to adapt to new situations.

A team of neuroscientists has discovered a special class of neurons in the prefrontal cortex that allows for flexible behavior and, when dysfunctional, may contribute to conditions such as schizophrenia and bipolar disorder. These long-range inhibitory connections synchronize gamma oscillations across the left and right prefrontal cortices, allowing the brain to alter its behavior at the right time.

This research may lead to new treatments for psychiatric disorders by targeting these long-range inhibitory connections.

sauce: conversation

Learning to be flexible and adapt when the world changes is a daily practice. Whether you hit a new construction site and need to reroute your commute, or download a new streaming app and relearn how to find your favorite shows, adapt to new situations and do what you know. Change is an essential skill.

To make these adaptations, the brain prefrontal cortex – Areas of the brain important for cognitive functions such as attention, planning and decision-making. However, it is unclear which specific circuits “instruct” the prefrontal cortex to update its activity patterns and change its behavior.

we team of neuroscientist We study how the brain processes information and what happens when this function is impaired. In a newly published study, a special class of neurons It is the prefrontal cortex that may enable flexible behavior, and their dysfunction can lead to conditions such as schizophrenia and bipolar disorder.

Inhibitory neurons and learning new rules

inhibitory neuron It weakens the activity of other neurons in the brain. Researchers have traditionally thought that they only send their electrical and chemical output to nearby neurons. However, we found that there is a specific class of inhibitory neurons in the prefrontal cortex that communicate over long distances with neurons in the opposite hemisphere of the brain.

We wondered whether these long-range inhibitory connections are involved in coordinating changes in activity patterns across the left and right prefrontal cortices. It can provide a signal.

To test the function of these long-range inhibitory connections, we observed mice performing a task that learned rules for receiving rewards and later had to adapt to the new rules to continue receiving rewards. In this task, a mouse dug a bowl to find hidden food. At first, the smell of garlic or the presence of sand in the bowl may indicate the location of hidden food. Certain cues associated with rewards are later changed, forcing mice to learn new rules.

found to silence long-range inhibitory connections between the left and right prefrontal cortices. mouse stopped moving, or stuck to one rule and prevented you from learning new ones. They couldn’t change gears, know that the old cues were now meaningless, and that the new cues were food cues.

EEG and Flexible Behavior

We also made surprising discoveries about how these long-range inhibitory connections create behavioral flexibility. Specifically, they synchronize a series of “brain waves” called “brain waves”. gamma oscillation It traverses two hemispheres. Gamma oscillations are rhythmic fluctuations in brain activity that occur approximately 40 times per second.

These fluctuations can be detected during many cognitive functions, such as performing tasks that require you to retain information in your memory, or making different movements based on what you see on your computer screen.

Scientists have observed the existence of gamma oscillations for decades, but their function has been controversial. Many researchers believe that the synchronization of these rhythmic fluctuations across different brain regions serves no purpose. Others speculate that synchronization between different brain regions enhances communication between those regions.

We discovered an entirely different potential role for gamma synchronization.When long-range inhibitory connections synchronize gamma oscillations across the left and right prefrontal cortices, they also Gate communication between them.

When mice learn to ignore previously established rules that no longer lead to reward, these connections synchronize gamma oscillations, stopping one hemisphere from sustaining unwanted activity patterns in the other. It looks like

In other words, long-range inhibitory connections seem to prevent input from one hemisphere from “disturbing” the other when trying to learn something new.

For example, the left prefrontal cortex can “remind” the right prefrontal cortex of the normal route to work. But when long-range inhibitory connections synchronize these two regions, these reminders are also blocked, allowing new patterns of brain activity to take hold in response to new commutes.

Finally, these long-distance suppression connections also induce long-term effectsCutting off these connections just once prevented the mice from learning the new rules after a few days. Conversely, rhythmic stimulation of these connections to artificially synchronize gamma oscillations can reverse these defects and restore normal learning.

Cognitive flexibility and schizophrenia

Long-range inhibitory connections play an important role in cognitive flexibility. One is the inability to properly update previously learned rules. Characteristic forms of cognitive impairment For psychiatric disorders such as schizophrenia and bipolar disorder.

also looking at research Defective gamma synchronization Abnormalities in classes of prefrontal inhibitory neurons, including those we studied in schizophrenia patients. In this context, our study suggests that treatments targeting these long-range inhibitory connections may help improve cognition in people with schizophrenia by synchronizing gamma oscillations. It suggests that

Many details about how these connections affect brain circuits remain unknown. For example, it is not known exactly which cells in the prefrontal cortex receive input from these long-range inhibitory connections to change activity patterns and learn new rules. We also do not know if there are specific molecular pathways that lead to long-term changes in neural activity.

Answering these questions may reveal how the brain flexes between maintaining and updating old information, potentially leading to new treatments for schizophrenia and other psychiatric disorders.

About this neuroscience research news

author: Vikas Sohar and Kathleen Cho
sauce: conversation
contact: Vikaas Sohal and Kathleen Cho – The Conversation
image: Image credited to Neuroscience News