Tbr1 immunoreactivity distinguishes short axon cells from surrounding tufted juxtaglomerular interneurons. (A,B) Neurolucida reconstruction of individual Neurog2-derived juxtaglomerular neurons and of the associated glomeruli that are negative (A) or positive (B) for Tbr1. A three-dimensional drawing of individual glomeruli is shown in blue. (C) Sholl analysis of the two populations of cells reveals a tufted arborization of the Tbr1-negative population of juxtaglomerular cells. (D) Quantification of the percentage of intrabulbar dendritic arborization. Note the very pronounced differences observed between the two cell populations, with Tbr1-negative juxtaglomerular neurons showing intraglomerular extending dendrites while Tbr1-positive neurons show preferential periglomerular dendrites. Scale bars: 20 μm in (A); 15 μm in (B-E); 10 μm in (F,G). Error bars indicate S.E.M.; *P < 0.05, determined by unpaired t-test.