Comparative Neuromorphology of Purkinje Neurons Across Species

Abstract

Neuromorphology of cells vary both across and within species, the differences of which contribute to a variety of cellular functions. Purkinje cells (PCs) in the cerebellum play a key role in the fine tuning of motor control and movement, and are characterized by their large soma and distinctive pattern of dendritic branching. However, outside of few selected taxa, the neuromorphology of PCs have not been well characterized. Here, we investigate PC neuromorphology in a representative reptile (leopard gecko), mammal (laboratory mouse), and bird (domestic chicken). Using a modified Golgi‐Cox protocol, differences in PC neuromorphology were quantified using Sholl and branched structure analyses. While PCs in all species demonstrated elaborate patterns of dendritic arborization, we quantified species‐specific differences in both cell size and branching complexity. The average dendritic length of PCs in geckos and mice were comparable, while those of chickens were almost twice as long. Chicken PCs are also characterized by a greater dendritic diameter and dendritic volume. Mouse and chicken PCs were significantly more complex than those of geckos, based on the number of dendritic terminals. Taken together, our findings demonstrate that even within the same cell type, there is considerable neuromorphological variation between species, potentially related to aspects of phylogeny, ecology, and functional morphology.Support or Funding InformationNatural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grants 400358 to MKV and 2019‐04989 to CDCB