The human olfactory system
The human sense of smell is remarkably keen, despite being commonly considered the insignificant “fifth” sense. The human nose outperforms the canine nose in detecting certain molecules, it can distinguish thousands of unique smells, and with a single sniff it can transport us back in time to reactivate distant memories and emotional states. The olfactory system is one of the few sites in the human brain where neurogenesis occurs throughout adulthood. And, through receptor neurons that touch air in the nasal cavities and project directly into the brain, the inside of the nose is the only place where the central nervous system makes direct contact with the external environment. With a number of unique properties compared to other sensory systems, the human olfactory system presents an increasingly attractive and powerful model for studying brain function under normal and pathological conditions.

Though the importance of smells in our lives may typically be underestimated, COVID has left millions of people with damaged or nonexistent smelling abilities, leading to a new appreciation of the profound emotional impact of its loss. Olfactory deficits have emerged as an early risk factor for many neurodegenerative and neuropsychiatric conditions. The pathology of both Parkinson’s Disease and Alzheimer’s Disease are thought to begin in olfactory structures, whose networks have direct, privileged access to limbic brain regions involved in memory, emotional processing and regulation of respiratory behavior (which is inextricably linked to odor sampling). Yet these connections to neuropathology are poorly understood, and olfactory abilities are not routinely tested in most neurological clinics. Despite the clinical importance of the olfactory system, we still lack understanding of some of its most basic anatomical, functional and electrophysiological properties, particularly in humans.

Overview of our research
We use a combination of neuroscience tools to study the human olfactory system at the behavioral, peripheral and central levels. We are also interested in the impact of nasal respiration (which is linked to odor sampling) on neural oscillations and human cognition and emotion, and in the composition of neural proteins in exhaled nasal breath in healthy and diseased participants. Techniques that we use include invasive stereo electroencephalography and direct electrical stimulation in neurosurgical epilepsy patients, functional neuroimaging including fMRI and DTI, surface EEG, psychophysics and computational analysis techniques.

Recent findings: