Heterogeneity of intrinsic excitability in Purkinje cells linked with longitudinal zebrin zones in the mouse cerebellum

Heterogeneous populations of Purkinje cells (PCs), classified into zebrin-positive (Z+) and - negative (Z-) types, are arranged into separate longitudinal zones and are involved in different types of cerebellar learning. However, the electrophysiological phenotype that is brought about by the zebrin expression has not been much clarified in PCs. We compared electrophysiological characteristics in the soma and parallel fiber (PF)-PC synapse in Z+ and Z- PCs located in identified vermal and hemispheric zones in cerebellar slices in zebrin-reporter mice. Intrinsic excitability, intrinsic plasticity and PF-PC synaptic long term potentiation (LTP) occurred more strongly in Z- Purkinje cells than in Z+ PCs. The enhanced intrinsic plasticity was correlated with the reduction of medium-time-course after-hyperpolarization (mAHP) only in Z- PCs. These differences, which seem to be produced by the zebrin-linked expression of other functional molecules, may tune Z+ and Z- PCs to zone-specific cerebellar functions.