AGE-RELATED AND REGION-SPECIFIC INCREASE IN NUMBER OF CONCENTRIC LAMELLAR BODIES IN AXON TERMINALS AND PRESYNAPTIC AXONS IN CENTRAL-NERVOUS-SYSTEM OF GROGGY MUTANT RAT

In some regions of the central nervous system (CNS) of the groggy rat, a mutant with a movement disorder, concentric lamellar bodies (CLBs) were formed in numerous axon terminals and presynaptic axons. These bo dies were counted electron microscopically in the lateral cerebellar n uclei of Slc:Wistar and groggy mutant rats at 20 to 180 days of age. I n the Slc:Wistar rat groups, the mean numbers of axonal CLBs were most ly under 1.0 per 100 mu m(2), except for the 30-day-old rat group whic h showed a value of 1.7. In the groggy rat groups, the numbers of axon al CLBs greatly increased from 40 days of age onward, reaching the max imum mean number of 23.7 per 100 mu m(2) in the 90-day-old rat group a nd subsequently decreasing; however, significant numbers were still pr esent in the 180-day-old rat group. Since these bodies have been repor ted to contain an acid phosphatase (ACPase), the regional specificity of their appearance in the CNS was examined by light and electron micr oscopic ACPase histochemistry. In the 90- and 180-day-old groggy rats, numerous particulate deposits of ACPase reaction products were found in the neuropil of the lateral, interposed and medial cerebellar nucle i, the superior, lateral and spinal vestibular nuclei, and the spinal gracile nuclei. By electron microscopy, the particulate deposits in th e cerebellar and vestibular nuclei were confirmed as the CLBs in axon terminals, while those in the gracile nuclei were revealed to be the d ystrophic axons. Thus, it was suggested that the axon terminals and pr esynaptic axons, having a high capacity to form the CLBs in the groggy rats from 40 days of age onward, belong to the Purkinje cells.