TY - JOUR T1 - Amygdala Corticofugal Input Shapes Mitral Cell Responses in the Accessory Olfactory Bulb JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0175-18.2018 SP - ENEURO.0175-18.2018 AU - Livio Oboti AU - Eleonora Russo AU - Tuyen Tran AU - Daniel Durstewitz AU - Joshua G Corbin Y1 - 2018/05/22 UR - http://www.eneuro.org/content/early/2018/05/22/ENEURO.0175-18.2018.abstract N2 - Interconnections between the olfactory bulb and the amygdala are a major pathway for triggering strong behavioral responses to a variety of odorants. However, while this broad mapping has been established, the patterns of amygdala feedback connectivity and the influence on olfactory circuitry remain unknown. Here, using a combination of neuronal tracing approaches, we dissect the connectivity of a cortical amygdala (PmCo) feedback circuit innervating the mouse accessory olfactory bulb (AOB). Optogenetic activation of PmCo feedback mainly results in feed-forward mitral cell (MC) inhibition through direct excitation of GABAergic granule cells (GC). In addition, LED-driven activity of corticofugal afferents increases the gain of MC responses to olfactory nerve stimulation. Thus, through corticofugal pathways, the PmCo likely regulates primary olfactory and social odor processing.Significance Statement Olfactory inputs are relayed directly through the amygdala to hypothalamic and limbic system nuclei regulating essential responses in the context of social behavior. However, it is not clear whether and how amygdala circuits participate in the earlier steps of olfactory processing at the level of the olfactory bulb. Unraveling the organization of this circuitry is critical to understand the function of amygdala circuits. Combining cre-dependent viral tracing with optogenetic-assisted patch clamp electrophysiology, the present work maps the synaptic connectivity and physiology of a cortical amygdala pathway innervating primary olfactory circuits. ER -