Genetic technique is a step toward strategy to help people with autism better process visual cues
Using a genetic technique that allows certain neurons in the brain to be switched on or off, UCLA scientists reversed a sensory impairment in mice with symptoms of autism, enabling them to learn a sensory task as quickly as healthy mice.
The findings, which appear in the journal Nature Neuroscience, offer an intriguing glimpse of a potential strategy to help people with autism make sense of what their eyes see.
In humans, the ability to perceive visual information is critical to learning of all kinds, including the interpretation of social cues. In children with autism, avoiding eye contact and struggling to understand people’s feelings may be rooted in how their brains process visual information.
“The focus in autism has been trying to tackle social impairment. But if there is a deficit in learning due to being unable to process certain kinds of sensory input, it affects your development,” said Anubhuti Goel, a postdoctoral researcher in neurology at UCLA and the study’s first author. “We’re trying to identify early brain processes that will impact behaviors in children when they are older.”
For this experiment, Goel and colleagues at UCLA used mice with a similar mutation in the FMR1 gene as humans with fragile X syndrome, a genetic condition that is the most commonly inherited cause of autism in humans. Mice with the mutation share a number of autism symptoms with people with fragile X syndrome, including anxiety, reduced social interaction and an overreaction to sensory stimuli such as texture and sound.
The researchers trained mice on a visual discrimination task, where the goal for the mice was to lick a drop of water in response to a specific visual cue on a screen. A pattern of parallel, black-and-white lines slanting a certain way signified the presence of a water drop; slanted a different way, there was no water drop. If the mice took too long to decide, the water drop disappeared — vacuumed up by the scientists.
On average, normal control mice mastered the strategy for getting water in about three days, whereas the mice with autism typically required five to nine days.
By recording brain activity in the mice, researchers found that the visual cortex of the fragile X syndrome mice, or FXS mice, had fewer and less finely tuned neurons called pyramidal cells. These excitatory neurons — the “gas pedal” in the brain — found in rodents, monkeys and humans, are responsible for perceiving the orientation of visual information, for example, the angle of the lines in the experiment. In addition, researchers found reduced activity in parvalbumin neurons, which are inhibitory neurons — the “brake pedal” — that work in concert with pyramidal cells, kicking them into gear and “tuning” them to respond to specific, or more general, bits of visual information.
The researchers wondered if they could prod those parvalbumin cells into working harder, which would in turn stimulate the pyramidal cells.
They targeted the parvalbumin cells with a genetic technique called DREADD, which stands for Designer Receptors Exclusively Activated by Designer Drugs. They injected the fragile X syndrome mice with a virus carrying the genes for these special designer receptors; once inside the mouse’s parvalbumin cells, the virus generates the DREADD receptors. Next, a drug administered intravenously reached those receptors and activated the parvalbumin cells.
Once the fragile X syndrome mice with the designer receptors received the drug, they could learn the visual discrimination task as quickly as their healthy counterparts did. The impact of the designer drug lasted for three to four hours.
“These experiments shed light on the brain circuit problems behind those difficulties in autism, and hint at directions we can pursue for treatment in the future,” Goel said.
Goel’s next step will be figuring out what happens in the visual discrimination task with sensory distractors, such as flashing lights or loud sounds. Many autistic children and adults are unable to tune out such distractors, which could contribute to poor performance in school and anxiety in social settings. Fragile X syndrome mice, too, have sensory over-reactivity, which could impede their learning.
The Latest on: Autism
via Google News
The Latest on: Autism
- Autism spectrum disorder can be predicted from health checkups at 18 monthson August 3, 2020 at 7:32 am
An early diagnosis of autism spectrum disorder, a type of developmental disorder was found to be effective from routine health checkups of infants at 18 months of age.
- A 10-year-old with Autism wanted to create a Covid-19 memorial garden in his local park... and the council's response was amazingon August 3, 2020 at 6:25 am
As this site belongs to the Reach network, you have been automatically logged in to the site with your Reach account A 10-year-old with Autism wanted to create a Covid-19 memorial garden in his local ...
- Puddingstone Place Expands Innovative School Program With Remote Learning for Students on Autism Spectrumon August 3, 2020 at 5:31 am
Puddingstone Place ™, LLC is a service provider for individuals with autism and other developmental disabilities with the goal to enhance communication, support behavioral changes, and improve overall ...
- Alteration of calcium channel signaling may explain the mechanism of autism spectrum disorderon August 3, 2020 at 5:20 am
Autism spectrum disorder (ASD) is a heterogeneous disorder initiated early in development and characterized by abnormal social communication. Accumulating evidence supports the idea that specific ...
- Mini Nurse's Uniform Eases Hospital Anxiety For 7-Year-Old With Autismon August 3, 2020 at 4:51 am
The mini uniform scheme is a relatively new initiative set up by Ruth May, the chief nursing officer for England, with a view to inspiring children and young people to take up a c ...
- Alternative Baseball provides positive experience for people with autism, disabilities; hopes to bring teams to Dallas-Fort Worthon August 2, 2020 at 9:32 pm
In 2016, Duncan founded the Alternative Baseball Organization (ABO) — a 501(c)(3) non-profit that provides a baseball experience for people with autism and other disabilities. "To find a team that was ...
- Netflix's 'Love on the Spectrum' updates both reality dating shows and portrayals of autismon July 31, 2020 at 5:58 pm
“Love on the Spectrum” is the latest of Netflix’s summer reality dating show releases — a programming ploy harkening back to the beginning of the reality television era — and, as part of its ...
- Sangamo and Novartis join forces to create gene therapies for autism and other brain disorderson July 30, 2020 at 2:28 pm
Bay Area biotechnology company Sangamo Therapeutics has teamed up with multinational pharmaceutical giant Novartis International AG to take on autism spectrum disorder and other neurodevelopmental ...
- New Therapy Center for Children with Autism Opens in Rockfordon July 30, 2020 at 11:51 am
ROCKFORD, Ill., July 30, 2020 /PRNewswire/ -- Caravel Autism Health has opened the doors to a new 6,000-square-foot center in Rockford that is designed for children with autism and their families.
via Bing News