Altered axon terminals containing concentric lamellar bodies were obse
rved in cerebellar and vestibular nuclei of the Mongolian gerbil. The
terminals increased in number from 30 days of age onward, and reached
about tenfold at 360 days. The numbers were the same in two gerbil str
ains with different susceptibility to spontaneous motor seizures by va
rious stimuli, but about threefold those in Slc:Wistar rat.