The geometry of the glutamatergic mossy-parallel fibre and climbing fibre inputs to cerebellar cortical Purkinje cells has powerfully influenced thinking about cerebellar functions. The compartmentation of the cerebellum into parasagittal zones, identifiable in olivo-cortico-nuclear projections, and the trajectories of the parallel fibres, transverse to these zones and following the long axes of the cortical folia, are particularly important. Two monoaminergic afferent systems, the serotonergic and noradrenergic, are major inputs to the cerebellar cortex but their architecture and relationship with the cortical geometry are poorly understood. Immunohistochemistry for the serotonin transporter (SERT) and for the noradrenaline transporter (NET) revealed strong anisotropy of these afferent fibres in the molecular layer of rat cerebellar cortex. Individual serotonergic fibres travel predominantly medial-lateral, along the long axes of the cortical folia, similar to parallel fibres and Zebrin II immunohistochemistry revealed that they can influence multiple zones. In contrast, individual noradrenergic fibres run predominantly parasagittally with rostral-caudal extents significantly longer than their medial-lateral deviations. Their local area of influence has similarities in form and size to those of identified microzones. Within the molecular layer, the orthogonal trajectories of these two afferent systems suggest different information processing. An individual serotonergic fibre must influence all zones and microzones within its medial-lateral trajectory. In contrast, noradrenergic fibres can influence smaller cortical territories, potentially as limited as a microzone. Evidence is emerging that these monoaminergic systems may not supply a global signal to all of their targets and their potential for cerebellar cortical functions is discussed.

谷氨酸能的苔藓平行纤维和小脑皮层浦肯野细胞的爬升纤维输入的几何形状对小脑功能的思维产生了很大的影响。小脑分隔成矢状皮质-核-核突起可辨认的矢状旁区域，以及平行于这些区域并遵循皮质叶面长轴的平行纤维的轨迹，尤其重要。血清素能和去甲肾上腺素能是两个单胺能传入系统，是小脑皮层的主要输入，但对它们的结构和与皮层几何形状的关系知之甚少。血清素转运蛋白（SERT）和去甲肾上腺素转运蛋白（NET）的免疫组织化学显示，这些传入纤维在大鼠小脑皮层的分子层中具有很强的各向异性。单独的血清素能纤维主要沿着皮质叶的长轴沿内侧行，类似于平行纤维，Zebrin II免疫组织化学表明它们可以影响多个区域。相比之下，单个去甲肾上腺素能纤维主要在下颌旁运行，其尾状尾端范围明显长于其内侧-外侧偏斜。它们在当地的影响区域在形式和大小上与已确定的微区相似。在分子层中，这两个传入系统的正交轨迹暗示了不同的信息处理。一条单独的血清素能纤维必须影响其内侧-外侧轨迹内的所有区域和微区域。相比之下，去甲肾上腺素能纤维可影响较小的皮质区域，可能仅限于微区。