Reeler

This is caused by the profound underdevelopment of the mouse's cerebellum, a segment of the brain responsible for locomotion.

In the reeler neocortex, cortical plate neurons are aligned in a practically inverted fashion ("outside-in").

[1] In the dentate gyrus of hippocampus, no characteristic radial glial scaffold is formed and no compact granule cell layer is established.

[2] Therefore, the reeler mouse presents a good model in which to investigate the mechanisms of establishment of the precise neuronal network during development.

[17] In the later years, histopathological studies revealed that the reeler cerebellum is dramatically decreased in size and the normal laminar organization found in several brain regions is disrupted (Hamburgh, 1960).

A reeler mouse
Brain slices of wildtype and reeler mice
Corticogenesis in a wild-type mouse. First neurons to take their place are the subplate neurons (yellow). Next come the cortical plate neurons (black), which migrate past the subplate level. Later-generated neurons drawn to be increasingly more bright.
Corticogenesis in a reeler mutant mouse. Note the so-called "inverted cortex", disorganized cellular layers, oblique angles of radial glia fibers.