Florida Atlantic: Groundbreaking Genetics

Florida Atlantic neuroscientists recently discovered a genetic mutation that explains different behaviors in males and females.

Neuropsychiatric disorders like Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) are found in four times as many boys as girls, but there’s limited science that explains this disparity – or other major sex-related differences found in these disorders.

The researchers looked at how this genetic variant affects ADHD and ASD through the dopamine activity in the brain. Both disorders are connected to dopamine, a vital neurotransmitter that regulates activities like motor function, attention, motivation, learning ability and social behavior. Dopamine is also the target of go-to medications to treat these disorders, including Adderall and Ritalin.

“We found a fundamental difference in the biology of the brain between males and females, specifically with how the dopamine systems work,” said Randy Blakely, Ph.D., professor of biomedical science in FAU’s Charles E. Schmidt College of Medicine and executive director of FAU’s Stiles-Nicholson Brain Institute.

Blakely led the study, published in the journal Molecular Psychiatry, in collaboration with Adele Stewart, Ph.D., first author on the report, research assistant professor of biomedical science in the Charles E. Schmidt College of Medicine and member of the Brain Institute. Blakely and Stewart found that the genetic mutation affects how dopamine is controlled in the brain, by essentially reversing the function of a protein whose primary role is to regulate dopamine.

“This mechanism in the brain sends males versus females on a totally different trajectory of behaviors,” Stewart said.

Based on the experiments, male mice were impulsive, less social and hyperactive, but females were anxious, had memory issues and struggled to recognize new things.

“Disorders that we define behaviorally could have completely different mechanistic underpinnings,” Stewart said. “And ultimately, we need to know what those biological underpinnings are, if we’re going to effectively treat them.”