title: Neurons expressing trace amine-associated receptors project to discrete glomeruli and constitute an olfactory subsystem.
abstract: Some chemoreceptors of the trace amine-associated receptor (TAAR) family detect innately aversive odors and are proposed to activate hardwired olfactory circuits. However, the wiring of TAAR neurons, the regulatory mechanisms of Taar gene choice, and the subcellular localization of TAAR proteins remain unknown. Here, we reveal similarities between neurons expressing TAARs and odorant receptors (ORs), but also unexpected differences. Like ORs, TAARs seem to be monoallelically expressed and localized both in cilia, the site of odor detection, and in axons, where they may participate in guidance. TAAR neurons project to discrete glomeruli predominantly localized to a confined bulb region. Taar expression involves different regulatory logic than OR expression, as neurons choosing a Taar5 knockout allele frequently express a second Taar without silencing the deleted allele. Moreover, the epigenetic signature of OR gene choice is absent from Taar genes. The unique molecular and anatomical features of the TAAR neurons suggest that they constitute a distinct olfactory subsystem.
authors: Department of Neuroscience, Brown University, Providence, RI 02912, USA.
authors: Mark A
authors: MA
authors: Johnson
authors: Lulu
authors: L
authors: Tsai
authors: Dheeraj S
authors: DS
authors: Roy
authors: David H
authors: DH
authors: Valenzuela
authors: Colleen
authors: C
authors: Mosley
authors: Angeliki
authors: A
authors: Magklara
authors: Stavros
authors: S
authors: Lomvardas
authors: Stephen D
authors: SD
authors: Liberles
authors: Gilad
authors: G
authors: Barnea
mesh_terms: D000483:Alleles; D000818:Animals; D001369:Axons / Q000378:metabolism; D003712:Dendrites / Q000378:metabolism*; D017353:Gene Deletion; D006570:Heterochromatin / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D005810:Multigene Family; D019006:Neural Cell Adhesion Molecules / Q000378:metabolism; D009830:Olfactory Bulb / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D011984:Sensory Receptor Cells / Q000378:metabolism*
chemical_list: D006570:Heterochromatin; C108768:Ncam2 protein, mouse; D019006:Neural Cell Adhesion Molecules; D043562:Receptors, G-Protein-Coupled