Critical genetic fact comes to light in treatment for ADHD

The brain constantly receives information, and focus depends on its ability to filter out distractions and pick up on what matters.

Attention disorders such as attention-deficit hyperactivity disorder (ADHD) involve a breakdown in our ability to separate signal from noise.

Stimulant medications improve attention by boosting activity in circuits known to manage attention, such as the prefrontal cortex (PFC).

A new study has now discovered a surprising potential alternative strategy, which may be used to reduce background activity as a way of turning down extraneous noise.

Headed by Priya Rajasethupathy, MD, PhD, head of the Skoler Horbach Family Laboratory of Neural Dynamics and Cognition at The Rockefeller University, researchers showed that a gene called Homer1 plays a critical role in shaping attention in just that way.

Their studies in mice depicted that animals with lower levels of two specific versions of the gene experienced quieter brain activity and had an improved ability to focus.

The team says the findings may be the first step towards a novel therapeutic approach to calming the mind, with implications for ADHD as well as related disorders characterized by early sensory disturbances already linked to Homer1, such as autism and schizophrenia.

“The gene we found has a striking effect on attention and is relevant to humans,” said Rajasethupathy, who is senior author of the team’s published paper in Nature Neuroscience, titled “Gene that Improves Attention in Mice Could Point to Mind-Calming Therapeutic Strategies for ADHD.”

Animals are “bombarded with a constant stream of sensory inputs,” the authors wrote, yet have limited capacity with which to process them. “A mechanism for filtering, prioritizing and directing mental assets is required to prevent sensory overload and enable meaningful comprehension; this process of sensory selection and prioritization is described as attention,” they stated.

The PFC plays an important role in mediating attention control, and many ADHD medications work in the PFC to boost attention. However, the team noted, “The genetic factors and resulting neural circuit physiology driving variation in attention are poorly understood.”