For seven consecutive days and nights, Dipesh Chaudhury did not leave his UCLA laboratory. He slept beneath his desk, emerging every six hours wearing Russian night-vision goggles with one broken lens to measure how mice learned around the clock. On Christmas Day, his mentor brought food. The experiment could not stop.
That weeklong study became one of his most-cited papers. More importantly, it launched a career-defining fascination with circadian rhythms, the biological clocks governing when we sleep, wake, and learn.
“That week changed everything,” Chaudhury reflects. “I realized the brain doesn't work on our schedule; it works on its own clock.”
Years later, that interest led him to the Mount Sinai School of Medicine, where he studied how brain reward circuits influence resilience or vulnerability to stress. This work sparked his curiosity about whether sleep and circadian rhythms differ between the two, leading to the discovery that mice prone to stress already showed disrupted sleep before any trauma occurred.
The finding suggested something profound about mental illness. What if the warning signs appear not in behavior or mood, but in sleep itself?
A mind for science
Born in Malaysia and educated across three continents, Chaudhury's path to neuroscience began with photosynthesis. A biology lesson in the UK on biochemical pathways struck him as remarkable, bringing physics and biology together in a way that captivated him.
At the University of London's School of Pharmacy, molecular neuroscience lectures revealed something even more extraordinary: how individual cells give rise to consciousness itself. “These neuronal cells, when connected in networks, create everything that makes us human,” Chaudhury explains. “Consciousness, culture, creativity, all emerging from cells working together.”
Following his PhD at the Open University under renowned neuroscientist Professor Steven Rose, Chaudhury moved through postdoctoral positions at UCLA, CNRS in Marseille, Cornell University, and the Mount Sinai School of Medicine.
At UCLA, working under fellow neuroscientist Professor Christopher Colwell in a newly established laboratory, he explored circadian rhythms and their connection to learning and memory. The work was painstaking but rewarding, measuring behavioral changes for days on end.
Why do we need sleep? Professor Chaudhury explains.
The breakthrough
At Mount Sinai, Chaudhury used an established stress model to study how brain reward circuits regulate resilience or susceptibility to stress. While applying this model, he began to consider how stress might also shape circadian rhythms and sleep–wake cycles.
Using genetically similar mice, he observed that populations naturally divide into those resilient to stress and those susceptible, much like in humans. “Just like in human populations, some people deal with stress well, some don’t,” he notes.
His breakthrough came when his postdoc measured sleep patterns before exposing mice to stress. The vulnerable mice already exhibited fragmented sleep, constantly transitioning between states rather than cycling through healthy stages. After stress, their sleep deteriorated further, resembling that of patients with insomnia.
“If subtle sleep patterns predict stress vulnerability, they could identify at-risk individuals entering high-pressure professions,” says Chaudhury. “More crucially, understanding the biological mechanisms might enable treatments that bypass sleep deprivation, a technique sometimes used for depression that carries significant quality-of-life costs.”
Chaudhury's recent findings suggest resilient mice adapt better to environmental changes, responding more dynamically when circadian rhythms are disrupted. "I think resilient mice are better adapted to environmental change, which makes sense for survival," he says. "Your clock allows you to entrain to your environment."
The resilient mice, he discovered, undergo what he calls "active coping processes," their biology buffering against stress-induced changes that overwhelm vulnerable animals. Collaborative work with psychiatric departments found similar molecular changes in postmortem brain tissue from patients with depression.
Turning insight into action
Today, as associate professor of biology at NYU Abu Dhabi, Chaudhury uses animal models of stress alongside cellular and molecular approaches to uncover the biological links between stress, circadian rhythms, and the sleep–wake cycle. He hopes his findings will inform the development of better treatments for mood disorders in humans.
"If we understand the biological connection, we can develop therapeutics by manipulating the biology of sleep and then treat mood disorders," he explains.
The research carries urgency. Stress-related disorders are rising globally, driven partly by modern life's disruption of natural rhythms: shift work, constant travel, and smartphone screens replacing darkness. His laboratory is also developing research into whether sleep patterns could serve as early markers for Parkinson's disease and multiple sclerosis.
For Chaudhury, unraveling the connections between sleep and mental health represents more than scientific curiosity. Understanding these biological pathways could transform how we treat some of humanity's most common disorders.
"If someone has PTSD, if their sleep cycle makes them more vulnerable, then maybe you can manipulate those circuits or molecular pathways and treat PTSD by making sleep better," he says. "Ultimately, it's about quality of life."
