Learning-Dependent Structural Plasticity in the Adult Olfactory Pathway

• Type of Material: Article
• Authors: Seth V. Jones, Emory University; Dennis Clarence Choi, Emory University; Michael Davis, Emory University; Kerry Ressler, Emory University
• Language: English
• Date: 2008-12-03
• Publisher: Society for Neuroscience
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2008 Society for Neuroscience
• Final Published Version (URL): http://www.jneurosci.org/content/28/49/13106.long
• Title of Journal or Parent Work: Journal of Neuroscience Nursing
• ISSN: 0270-6474
• Volume: 28
• Issue: 49
• Start Page: 13106
• End Page: 13111
• Grant/Funding Information: Support was provided by NIH (MH069884; DA019624 - KJR, R37 MH47840 - MD), NARSAD, the Center for Behavioral Neuroscience (NSF agreement IBN-987675), Burroughs Wellcome Fund, and by an NIH/NCRR base grant (P51RR000165) to Yerkes National Primate Research Center.
• Keywords: glomerulus; fear; learning memory; plasticity; olfactory; learning
• Research Categories: Biology, Neuroscience; Psychology, Behavioral

Abstract

Olfactory learning in humans leads to enhanced perceptual discrimination of odor cues. Examining mouse models of both aversive and appetitive conditioning, we demonstrate a mechanism which may underlie this adult learning phenomenon. Topographically-unique spatial wiring of the olfactory system allowed us to demonstrate that emotional learning of odor cues alters the primary sensory representation within the nose and brain of adult mice. Transgenic mice labeled at the M71 odorant receptor (specifically activated by the odorant acetophenone), were behaviorally trained with olfactory-dependent fear conditioning or conditioned place preference using acetophenone. Odor-trained mice had larger M71-specific glomeruli and an increase in M71-specific sensory neurons within the nose compared to mice that were untrained, trained to a non-M71 activating odorant, or had non-associative pairings of acetophenone. These data indicate that the primary sensory neuron population and its projections may remain plastic in adults, providing a structural mechanism for learning-enhanced olfactory sensitivity and discrimination.