Learning and memory rely on the strength of connections between neurons in the brain. These connections are called synapses. Synapses are not fixed but plastic and changeable. When they can’t or don’t change, behavioral disorders may occur.
Researchers from Duke University are looking at what happens when those connections are not as adaptable as they should be in the basal ganglia, the brain’s command center for turning information into action.
“The basal ganglia is the part of the brain that drives the car when you’re not thinking too hard about it,” said Nicole Calakos, Duke University neurologist and neuroscientist. This area of the brain is where neuroscientists are looking for the roots of obsessive-compulsive disorder (OCD), Huntington’s, Parkinson’s, and aspects of autism spectrum disorder.
Defects may lead to compulsive behaviors and autistic disorders
Calakos is mapping the defects in the circuitry of the basal ganglia that underlie compulsive behavior. To do this, she is studying mice that have a synaptic defect that manifests itself as something like obsessive-compulsive behavior.
Former colleague Guoping Feng developed the mice before moving to another position at the McGovern Institute for Brain Research at MIT. Feng was also studying synapses by knocking out genes one at a time to check the effect. One set of mice developed facial lesions because they couldn’t stop grooming themselves exhibiting a characteristic of OCD.
While researching these mice, Calakos’ group discovered that metabotropic glutamate receptors, or mGluRs, were overactive and left their synapses less able to change. It may be that the over-activity of these receptors can cause many aspects of the autistic spectrum disorder Fragile X mental retardation.
New understandings may bring new treatments
“It’s an example of synaptic plasticity going awry,” Calakos explained. “They’re stuck with less adaptable synapses.”
Calakos is now trying to determine whether drugs that inhibit mGluRs can be used to improve their behavior. This may lead to new understandings of compulsive behaviors.
Source: MedicalNewsToday, Duke University