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UC Davis Health System

UC Davis Health System

Toxicologist builds on marine biology roots to find potential causes of autism

Photo of Issac Pessah during a scub diving trip
Originally a marine biologist, Pessah still enjoys exploring the ocean while investigating potential environmental causes of autism.

When Isaac Pessah wants to get away from it all, he heads to water.

The director of the Center for Children's Environmental Health and Disease Prevention is well known as a leading expert on the potential environmental causes of autism. Not nearly as many folks know he's also an avid sailor. He likes to get out on San Francisco Bay and negotiate 30-knot winds. Or pass through the Golden Gate onto the open ocean and ply northern California's rugged coastline.

It's not just the scenery and the thrill that he's after. It's also the escape and the responsibility.

“It's a wonderful way to get your mind off things,” Pessah said. “You're totally responsible for yourself and anyone else on the boat. You know that if you make good decisions, you'll bring the boat back.”

Pessah's boldness around water can be traced to his northeastern roots. Growing up in upstate New York and attending Cornell University in the late 1970s, he'd sometimes head north to Canada and the St. Lawrence River, where for fun he'd ice dive.

At Cornell, he at first chose to major in marine biology, but changed his mind during graduate school at the University of Maryland. “I realized that I would have very little chance to make a real difference as an ecologist,” said Pessah.

Part of the reason for that shift was his growing interest in cells — tiny but powerful players in human health — and how they react to external influences. At first, he studied the acetylcholine receptor — a membrane protein that binds to neurotransmitters. “This was exciting,” said Pessah. “It was the very first time an ion channel was being purified using venom toxin from the Asian cobra. It made a huge difference in the direction I would go for a career.”

His interests in cell-environmental connections deepened during postdoctoral studies at UC Berkeley, where he began investigating calcium signaling. Here, he discovered the ryanodine receptors that have been linked to environmental susceptibility and diseases of skeletal and cardiac muscle as well as Alzheimer's disease.

Today, as a professor of molecular biosciences at UC Davis, Pessah is a recognized authority on how certain anthropogenic substances in the environment — like mercury, PCBs and natural toxins isolated from scorpions or marine sponges — can disrupt calcium signaling in muscle, nerve and immune cells. He has quickly risen to prominence as an autism scientist, given that the immune and nervous systems of children with autism are impaired, and he is now exploring whether mutations in the genes that code for ryanodine recptors contribute to autism susceptibility.

While happy with his career, Pessah maintains a passion for marine biology in his personal life. It's an interest he shares with his wife, Bea, whom he met during a graduate school statistics course. By the second class hour, it was apparent that she shared his enthusiasm for the ocean. They were off to the Bahamas for turtle rescue the very next break.

Clearly, Pessah's motivation appears to spring from a deep-seated need to travel in uncharted waters — and to puzzle things out as he goes.

“I enjoy finding the next little piece of information,” he said.