Purkinje neurons in mouse cerebellum

Coronal section of a mouse cerebellum, with Purkinje neurons (the bright "splash," in red) — cells essential for motor learning, balance, and movement coordination. A diagonal cut through the cerebellar fold captures several rows of these cells, which normally align in a single layer, in one plane.

Purkinje cells sit atop the granular layer (DNA, blue) and densely express the voltage-gated potassium channel Kv3.3 (red), which enables the rapid, high-frequency firing needed for precise motor control. In humans, Kv3.3 mutations cause spinocerebellar ataxia type 13, a neurodegenerative disease that damages and kills Purkinje neurons. Here, we examined Kv3.3 expression in mice carrying the equivalent mutation (Kv3.3-N483C) - a strain that does indeed show tremors.