TNFα and its receptors increased as demyelination proceeded. A-B: Quantification of mRNA for TNFα (A) and its receptors (B). The copies of mRNA for TNFα have increased in twi/twi (■) after PND 30, especially in the cerebellum, when compared with those in +/+ (▴). Those for TNFR1 in the cerebellum have increased in twi/twi after PND 30. The copies of mRNA for TNFR2 have increased in twi/twi only after PND 40, when compared with those for +/+, but the difference was not significant (B). Bar represents mean ± SE. * p < 0.01. C-F: TNFα immunostaining in the cerebellum. There are no TNFα-positive cells in the cerebellum of twi/twi mice at PND 20 (C). Immunoreactive cells for TNFα are progressively increased in number in the twi/twi cerebellar white matter between PND 30 (D) and PND 40 (E). In contrast, there are no TNFα positive cells in +/+ brains at any ages examined (F). Tw and W represent twi/twi and wild-type mice, respectively. The data represent mean ± SE. IG: internal granular layer, CWM: cerebellar white matter. Scale bar = 50 μm.