For as long as time, poets to philosophers have deeply romanticised that ethereal connection between our human sense of smell and memory.

Neurobiologists at the University of Toronto have identified a mechanism that allows the brain to re-create vivid sensory experiences from memory – shedding light on how sensory-rich memories are created and stored in our brains.

There is a strong connection between memory and olfaction owing to their common evolutionary history. Examining this connection in mice, Aqrabawi, a PhD candidate in the Department of Cell & Systems Biology, and graduate supervisor Professor Jun Chul Kim in the Department of Psychology at U of T found that information about space and time integrate within a region of the brain important for the sense of smell — yet poorly understood — known as the anterior olfactory nucleus (AON).

“When these elements combine, a what-when-where memory is formed,” said Aqrabawi. This is why you might have the ability to remember…

the smell of a lover’s perfume (the what) when you reminisce about your first kiss (the when and where).

“Given the early degeneration of the AON in Alzheimer’s disease, our study suggests that the odour deficits experienced by patients involve difficulties remembering the ‘when’ and ‘where’ odours were encountered,” said Kim.

This important research will continue to investigate the cause and detection of Alzheimer’s and aid in the design of better tests in the early identification and treatment of this disease.