Diego Restrepo, Ph.D. - Univ. of Colorado School of Medicine
Mar 05, 2020 @ 4:00 p.m.
This seminar will delve on understanding of valence (is the stimulus rewarded?) for the olfactory system – smell. Olfaction is a sensory system that deals with rapid decision-making on the basis of a complex fluctuating multi-dimensional input (the odorant plume). Volatile chemical features are detected by hundreds of olfactory receptors that convey information to the olfactory bulb (OB). A particularly interesting feature of this sensory system is that early processing of the signal on odorant identity in the OB is modified by centrifugal input from downstream brain areas. Here I will first discuss a recent study on circuit oscillations in the OB showing that contextual odorant identity (is the odorant rewarded?) can be decoded from peak theta frequency-referenced gamma frequency bursts of electrical activity in animals proficient in odorant discrimination, but not in naïve mice. Thus, as the animal learns to detect a rewarded odorant in an odorant associative learning task stimulus processing in the OB is altered, resulting in more accurate signal processing for the rewarded odorant, a process analogous to the auditory cocktail party effect (Losacco, Ramirez-Gordillo, et al. 2019, BioRxiv doi: https://doi.org/10.1101/758813). I will then follow with a study of the role of molecular layer interneurons (MLIs) of the cerebellum in ensuring quick decision making in an odorant discrimination task. The cerebellum, a structure classically known for efficient error correction in sensorimotor tasks, has recently been implied in processing reward in associative learning. Using two-photon microscopy and chemogenetics we find that MLIs have a role in learning odorant valence and speedy decision-making in the cerebellum (Ma et al., 2019, BioRxiv https://doi.org/10.1101/2019.12.14.876201). Finally, I will discuss how our multidisciplinary OPeN team is studying the circuit basis of the complex task of odorant plume navigation using custom-made miniature multiphoton miniature fiber coupled microscopes (Ozbay et al., 2018, doi: 10.1038/s41598-018-26326-3).
Medical Center | K-207 (2-6407)
Host: Univ. Rochester School of Medicine and Dentistry, Dept. Neuroscience, and the Del Monte Institute for Neuroscience