Julian P.
Meeks\, PhD
Associate Professor\, Department of Neuroscience
Associate Professor\, Department of Pediatrics - Joint
Associate Profe
ssor\, Department of Pharmacology and Physiology - Joint
University of
Rochester Medical Center
Each year\, a former recipient of the James L. O’Leary Prize f or Research in Neuroscience competition is invited to present the annua l O’Leary Lecture and also be a guest judge at the prize competition.
Across the animal kingdom\, chemical cues play cen tral roles in supporting survival and reproduction. Chemosensory systems al low animals to sense excreted molecules that distinguish self from non-self \, identify potential friends and foes\, and evaluate potential mates. In v ertebrates\, the juxtaposition of strongly conserved aspects of physiology with each species' need to interpret their chemical environments places che mosensory systems at an interesting neurobiological intersection. For examp le\, all vertebrates utilize bile acids (digestive steroids) to absorb diet ary lipids\, and excrete bile acids in feces to prevent toxic buildup. Most vertebrates\, including important preclinical model organisms (including z ebrafish\, mice\, and rats) sense bile acids\, but we do not yet understand how or why they evolved such a capacity. Using population Ca2+ imaging\, m ass spectrometry\, and modeling\, we investigated bile acid chemosensation in mice. We found that fecal bile acid patterns - and not species-bespoke m olecules - support discrimination of vegetarian reptiles from rodent predat ors. We found that the mouse vomeronasal organ can use patterns of bile aci d excretion (chemical "fingerprints") to partially decode reptile species a nd diet. When we compared bile acid "fingerprints" of mice with different g ut microbiomes to vomeronasal neuron sensitivities\, we found tight couplin g between the two\, suggesting that the vomeronasal system is optimized for sensing conspecific gut health. Finally\, we present early work investigat ing the potential for early life chemosensory experience to shape pheromone processing in adulthood. These studies suggest that the vomeronasal system \, despite its reputation as a fixed pathway for detecting rare\, unique mo lecules\, is a flexible sensory system optimized to decode the chemical fin gerprints of biologically relevant states.
CATEGORIES:O'Leary Lecture LOCATION:Neuroscience Research Building Auditorium GEO:38.635602;-90.254892 ORGANIZER;CN="Shea":MAILTO:shea.stewart@wustl.edu URL;VALUE=URI:https://neuroscience.wustl.edu/events/event/2026-oleary-lectu re-julian-p-meeks/ END:VEVENT BEGIN:VTIMEZONE TZID:America/Chicago BEGIN:DAYLIGHT TZOFFSETFROM:-0600 TZOFFSETTO:-0500 DTSTART:20260308T080000 TZNAME:CDT END:DAYLIGHT END:VTIMEZONE END:VCALENDAR