RT Journal Article SR Electronic T1 Toric Spines at a Site of Learning JF eneuro JO eNeuro FD Society for Neuroscience SP ENEURO.0197-19.2019 DO 10.1523/ENEURO.0197-19.2019 VO 7 IS 1 A1 Sanculi, Daniel A1 Pannoni, Katherine E. A1 Bushong, Eric A. A1 Crump, Michael A1 Sung, Michelle A1 Popat, Vyoma A1 Zaher, Camilia A1 Hicks, Emma A1 Song, Ashley A1 Mofakham, Nikan A1 Li, Peining A1 Antzoulatos, Evan G. A1 Fioravante, Diasynou A1 Ellisman, Mark H. A1 DeBello, William M. YR 2020 UL http://www.eneuro.org/content/7/1/ENEURO.0197-19.2019.abstract AB We discovered a new type of dendritic spine. It is found on space-specific neurons in the barn owl inferior colliculus, a site of experience-dependent plasticity. Connectomic analysis revealed dendritic protrusions of unusual morphology including topological holes, hence termed “toric” spines (n = 76). More significantly, presynaptic terminals converging onto individual toric spines displayed numerous active zones (up to 49) derived from multiple axons (up to 11) with incoming trajectories distributed widely throughout 3D space. This arrangement is suited to integrate input sources. Dense reconstruction of two toric spines revealed that they were unconnected with the majority (∼84%) of intertwined axons, implying a high capacity for information storage. We developed an ex vivo slice preparation and provide the first published data on space-specific neuron intrinsic properties, including cellular subtypes with and without toric-like spines. We propose that toric spines are a cellular locus of sensory integration and behavioral learning.