Impaired brain coordination leads to attention disorders

Abnormal attention between two brain regions can lead to attention deficit disorders, including schizophrenia, and major depression.

Schizophrenia a mental disorder characterised by abnormal social behavior and failure to understand reality.

People suffering from the same, face difficulty as they are unable to focus and display compulsive behavior.

A study suggests that these symptoms could be due to dysfunction in a gene--ErbB4, known as a risk factor for psychiatric disorders as it helps different brain regions to communicate an maintain a healthy neurotransmitter level in the brain.

The researchers who conducted the study also showed a mice lacking ErbB4 activity in specific brain regions performed poorly on timed attention tasks. The mice struggled to pay attention and remember visual cues associated with food. The scientists describe it as "top-down attention".

Top-down attention is related to focus and people who lack it are at a higher risk for attention deficit hyperactivity disorder (ADHD).

"The results reveal a mechanism for top-down attention, which could go wrong in attention disorders," said a corresponding author. "And since ErbB4 is a risk factor for schizophrenia, bipolar disorder, and major depression, the results provide insights into mechanisms of these disorders" he added.

The researchers studied the prefrontal cortex--normally associated with decision-making--and the hippocampus, a region that supports memory. These two regions coordinate for a variety of brain tasks, including memory and attention.

According to the study, ErbB4 coordinates a cascade of brain signals that "bridge" the two regions. ErbB4 itself encodes a receptor found on the surface of brain cells. It was also stated that when a protein (neuregulin-1) attaches to the ErbB4 receptor, it triggers a chain reaction that ultimately determines neurotransmitter levels in the prefrontal cortex and hippocampus. Without ErbB4, neurotransmitter levels go awry.

The study used a novel mouse model to study brain functions and are planning to use the novel mouse model to study how ErbB4 may coordinate brain activities, in an effort to learn more about mechanisms behind attention deficit disorders.

The results of this study were published in the Journal of Neuron.