Headshot of Sheena Josselyn.

Sheena Josselyn

Senior scientist, Hospital for Sick Children;
Contributing editor, The Transmitter

Sheena Josselyn is senior scientist at the Hospital for Sick Children (SickKids) and professor of psychology and physiology at the University of Toronto in Canada. She holds a Canada research chair in brain mechanisms underlying memory, and she is a fellow of the Royal Society of Canada and of the U.S. National Academy of Medicine.

Josselyn is interested in understanding how the brain encodes, stores and uses information. Her primary model organism is mice. Because several conditions (ranging from autism to Alzheimer’s disease) may stem from disrupted information processing, this basic knowledge in mice is critical not only for understanding typical human brain function, but for developing new treatment strategies for these conditions.

She received her undergraduate degrees in psychology and life sciences and an M.Sc. in clinical psychology from Queen’s University in Kingston, Canada. She received a Ph.D. in neuroscience/psychology from the University of Toronto, with Franco Vaccarino as her supervisor. She conducted postdoctoral work with Mike Davis of Yale University and Alcino Silva of the University of California, Los Angeles.

Josselyn has received numerous awards, including the Innovations in Psychopharmacology Award from the Canadian College of Neuropsychopharmacology, the Effron Award from the American College of Neuropsychopharmacology, the Andrew Carnegie Prize in Mind and Brain Sciences, and the Betty & David Koetser Award for Brain Research.

Explore more from The Transmitter

Two lab mice fighting.

From friend to foe: How the brain updates feelings toward others

A specific hippocampus-to-amygdala pathway reassigns emotional valence to a known individual, whereas the hippocampus’s own representation of that individual’s identity remains stable.

By Natalia Mesa
9 July 2026 | 5 min read
Illustration of scientist in lab coat looking at shelves of computer network models.

Mass-produced science is coming. What happens to scientists?

Artificial intelligence may soon enable researchers to generate high-quality science at a previously unimaginable speed. For science consumers—the public, medical patients, technology users—the likely effects will be positive. For scientists, the effects will be as disruptive as industrial mass production was for artisan manufacturers.

By Kenneth Harris
9 July 2026 | 9 min read
Adriano Aguzzi.

Neuropathologist not guilty of research misconduct, says university probe

The investigation determined that seven papers by corresponding author Adriano Aguzzi have “scientifically significant” errors, which Aguzzi attributes to his former students.

By Dalmeet Singh Chawla
8 July 2026 | 5 min read