title: Glomerulus-specific, long-latency activity in the olfactory bulb granule cell network.
abstract: Reliable, stimulus-specific temporal patterns of action potentials have been proposed to encode information in many brain areas, perhaps most notably in the olfactory system. Analysis of such temporal coding has focused almost exclusively on excitatory neurons. Thus, the role of networks of inhibitory interneurons in establishing and maintaining this reliability is unclear. Here we use imaging of population activity in vitro to investigate the mechanisms of temporal pattern generation in mouse olfactory bulb inhibitory interneurons. We show that activity of these interneurons evolves slowly in time but that individual neurons fire at reliable times, with a timescale similar to the slow changes in the patterns of odor-evoked activity and to odor discrimination. Most strikingly, the latency of a single granule cell is highly reliable from trial to trial during repeated stimulation of the same glomerulus, whereas this same cell will have a markedly different latency when a different glomerulus is activated. These data suggest that the timing of granule cell-mediated inhibition in the olfactory bulb is tightly regulated by the source of input and that inhibition may contribute to the generation of reliable temporal patterns of mitral cell activity.
authors.affiliation: Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
authors.forename: Vikrant
authors.initials: V
authors.lastname: Kapoor
authors.forename: Nathaniel N
authors.initials: NN
authors.lastname: Urban
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D000634:Aminoquinolines / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods; D016257:Fura-2 / Q000378:metabolism; D066298:In Vitro Techniques; D053444:Inhibitory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D007395:Interneurons / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D051379:Mice; D008810:Mice, Inbred C57BL; D009415:Nerve Net / Q000166:cytology / Q000502:physiology* / Q000528:radiation effects; D009830:Olfactory Bulb / Q000166:cytology*; D018408:Patch-Clamp Techniques / Q000379:methods; D026902:Potassium Channel Blockers / Q000494:pharmacology; D011798:Quinaldines / Q000494:pharmacology; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects
chemical_list: D000634:Aminoquinolines; D026902:Potassium Channel Blockers; D011798:Quinaldines; C507002:4-amino-2-methylquinoline; D016257:Fura-2