QUANTITATIVE-ANALYSIS OF THE PURKINJE-CELL AND THE GRANULE CELL-POPULATIONS LN THE CEREBELLUM OF NUDE-MICE

In the nude mutant, a well-known model of athymia in mouse, abnormalit ies have been reported in the cerebellum, including a 45% reduction in cerebellar size and neuronal loss (Henderson et al., 1981). The prese nt work was aimed at reappraising the claimed anomalies by using quant itative cytological techniques. We counted the Purkinje and the granul e cells, on serial sagittal sections stained with thionin, in the cere bella of nude mice (nu/nu) compared with their Balb/c controls (+/+). The latero-lateral extent of the cerebellar cortex was statistically d ifferent (mean +/- standard deviation) between the nude (7.05 +/- 0.45 mm, n = 3) and the control mice (8.05 +/- 0.35 mm, n = 3) (Student's t-test, p < 0.05). The number of Purkinje cells was not statistically different (p = 0.98) between the nude mice (159,880 +/- 5,225, n = 3) and the control ones (160,060 +/- 12,300, n = 3). The number of granul e cells (x 10(6)) did not differ significantly (p = 0.40) in nude mice (m = 12.1 +/- 1.8, n = 3) from the controls (m = 13.2 +/- 0.8, n = 3) . Immunohistochemistry with a specific marker of Purkinje cells, calbi ndin protein, did not reveal any qualitative differences between the n ude and the control Purkinje cells. The only slight but significant di fference concerned the mean cross-sectional area of the Purkinje cell somas: 188.2 mu m(2) (n = 149) in the control animals and 176.3 mu m(2 ) (n = 150) in the nude mice, (p < 0.01). In conclusion, our data indi cate only a mild effect, if any, of the nude mutation upon the cerebel lar neuronal population.