Fig. 9.

Distribution of mGluR1α⁺ UBCs and CR⁺ UBCs in mouse nodulus and uvula as seen in coronal sections. The midline of each section is indicated with horizontal magenta colored line. Mid-to lateral zones 1-7 are marked with black dashed lines. Arrowheads indicate UBC rich bands in IXc/d;r2. a Typical mGluR1α immunolabeling; intense immunolabeling of Purkinje cell dendrites in ml and distinct immunopositivity in UBCs scattered throughout the gcl, especially in nodulus and IXc/d;r2. The midline zone 1 of IXc/d;r2 shows the highest UBC density, while the midline zones 1, 2 of Xvent and the lateral zones 6, 7 of vermis also contains dense mGluR1α⁺ UBC population. Inset a’ shows a representative mGluR1α⁺ UBC; intense staining in the brush (arrow) and subtle immunopositivity in soma (arrowhead). b Typical CR immunolabeling in UBCs and granule cells. The granule cells somata in gcl and their axons (parallel fibers) in the ml show intense immunopositivity in all cerebellar lobules (VIII/IXa and COP shown) except the nodulus and IXc;r2. These later structures contain a dense CR⁺ UBC population and CR⁺ mossy fibers. Purple dash line delineate an area (purple arrows) with notably dense population of CR labeled UBCs and mossy fibers. Inset b’ shows a representative CR⁺ UBC; intense staining in the brush (arrow) and cell body (arrowhead). c Schematic illustration of the CR⁺ (right side) UBC and mGluR1α⁺ UBC (left side) distributions in mid-to-later zones. Numbers indicate the density of UBCs (N/0.01mm²; for standard deviations see Supplementary Table 1). Midline zone 1 in IXc;r2 contains the highest density of both CR⁺ UBCs and mGluR1α⁺ UBCs (red colored zone). d A gradient map illustrates the distribution of UBC subclasses; CR⁺ (right side) and mGluR1α⁺ (left side). Red color is assigned to the highest cell density (max) of either CR⁺ UBCs or mGluR1α⁺ UBCs. The deep blue colored area contain hardly any UBCs. Scale bars a 200 μm (applies to a-d), inset a’ 10 μm (applies to insets a’, b’)