%0 Journal Article %A Annie Liu %A Nathaniel N. Urban %T Prenatal and Early Postnatal Odorant Exposure Heightens Odor-Evoked Mitral Cell Responses in the Mouse Olfactory Bulb %D 2017 %R 10.1523/ENEURO.0129-17.2017 %J eneuro %P ENEURO.0129-17.2017 %X Early sensory experience shapes the anatomy and function of sensory circuits. In the mouse olfactory bulb (OB), prenatal and early postnatal odorant exposure through odorized food (food/odorant pairing) not only increases the volume of activated glomeruli but also increases the number of mitral and tufted cells (M/TCs) connected to activated glomeruli. Given the importance of M/TCs in OB output and in mediating lateral inhibitory networks, increasing the number of M/TCs connected to a single glomerulus may significantly change odorant representation by increasing the total output of that glomerulus and/or by increasing the strength of lateral inhibition mediated by cells connected to the affected glomerulus. Here, we seek to understand the functional impact of this long-term odorant exposure paradigm on the population activity of mitral cells (MCs). We use viral expression of GCaMP6s to examine odor-evoked responses of MCs following prenatal and early postnatal odorant exposure to two dissimilar odorants, methyl salicylate and hexanal, which are both strong activators of glomeruli on the dorsal OB surface. Previous work suggests that odor familiarity may decrease odor-evoked MC response in rodents. However, we find that early food-based odorant exposure significantly changes MC responses in an unexpected way, resulting in broad increases in the amplitude, number, and reliability of excitatory MC responses across the dorsal OB.Significance Statement The structure and output of the olfactory bulb (OB) circuit can be modified by odor experience throughout both development and adulthood. The highly specific organization of this system lends itself to detailed analyses of how experience can shape the architecture of sensory system responses. Previous work demonstrated that prenatal and early postnatal odorant exposure using a food-based paradigm increased the number of primary projection neurons connected to activated glomeruli. This increase may have significant effects on odorant representation and OB output. In this study, we focus on understanding how this odorant exposure paradigm impacts the odor-evoked responses of one population of primary OB output neurons, the mitral cells. %U https://www.eneuro.org/content/eneuro/early/2017/09/25/ENEURO.0129-17.2017.full.pdf