Dr. Karl Deisseroth spent hours receiving congratulatory calls after learning early Monday that he had won the Nobel Prize in Physiology or Medicine for helping establish a new field of brain science known as optogenetics.

But the California scientist soon asked for a break from the celebrations for a much more routine responsibility preparing school lunches for his children.

His children were asleep at the family's home in Stanford while their father spoke with journalists and well-wishers in the early hours of the morning.

Deisseroth, 54, shared this year's medicine Nobel with German researchers Peter Hegemann and Georg Nagel for their work in optogenetics, a technique that uses light and genes to control neurons in living brains.

A self-described night owl, Deisseroth, a Howard Hughes Medical Institute investigator and Stanford University professor, often works past midnight.

After reviewing research papers and emailing students, he said he had just gone to bed when he received the call from the Nobel Assembly in Stockholm.

“I almost felt as if I'd lost the power of forming words,” he told The Associated Press, adding that he recovered after a minute or two.

He was soon able to take remote interviews with AP science reporters. Stanford's communications team helped arrange the interviews through a series of quick emails.

“No real sleep was achieved,” Deisseroth said about an hour after the Nobel announcement.

As the interviews continued by phone and Zoom, an AP photographer and videographer rushed to his Stanford home.

The photographer arrived around 3:30 a.m. and saw Halloween decorations outside the house, with only one light on inside. Unsure whether he had found the right home, he eventually knocked on the door.

Deisseroth's wife, Dr. Michelle Monje-Deisseroth, answered and welcomed the photographer inside. The Nobel laureate was sitting on the couch, taking calls.

Monje-Deisseroth, also an HHMI investigator and a Stanford pediatric neuro-oncologist, stayed beside her husband when she was not preparing coffee for Stanford communications staff who had joined the celebration.

Deisseroth said he was surprised that his research had received the Nobel Prize. His wife, however, was not surprised.

He discussed his research with Hegemann and Nagel and its potential impact on patients.

“As a physician-scientist, I am a psychiatrist. I care about patients and my patients who have autism, who have depression,” he said, adding that he valued the hope the research could bring.

At the same time, he said he remained interested in basic science and in understanding how the brain works, processes information and produces the qualities that make humans unique.

After finishing the interviews, Deisseroth told Stanford staff that he needed an hour-long break starting at 6:30 a.m.

His children would soon wake up and needed lunches before heading to school, he said.

When a Stanford representative wondered whether neighbours might be disturbed by the late-night activity, Monje-Deisseroth appeared unconcerned.

They live in faculty housing, she said, adding that “there are a lot of Nobels in the neighborhood.”