Temporal Processing in the Olfactory System: Can We See a Smell?

Sensory processing circuits in the visual and olfactory systems receive input from complex, rapidly changing environments. Although patterns of light and plumes of odor create different distributions of activity in the retina and olfactory bulb, both structures use what appears on the surface similar temporal coding strategiesto convey information to higher areas in the brain. We compare temporal coding in the early stages of the olfactory and visual systems, highlighting recent progress in understanding the role of time in olfactory coding during active sensing by behaving animals. We also examine studies that address the divergent circuit mechanisms that generate temporal codes in the two systems, and find that they provide physiological information directly related to functional questions raised by neuroanatomical studies of Ramon y Cajal over a century ago. Consideration of differences in neural activity in sensory systems contributes to generating new approaches to understand signal processing. © 2013 Elsevier Inc.This work was partially supported by NIH grants DC00566 (D.R.), DC04657 (D.R.), F32-DC011980 (D.H.G.), BFU2010-15564 and BFU2010-21377 from the Spanish Ministerio de Ciencia e Innovacion (L.L.-M.), and the Howard Hughes Medical Institute (T.J.S.).Spanish Ministerio de Ciencia e InnovacionHoward Hughes Medical InstitutePeer Reviewe