Fig. 5.

Axotrophin immunohistochemistry in cerebellum of tau knock-out and human tau gene transgenic mice. (A) Brain sections were labeled with the affinity-purified anti-AxoCT antibody and visualized with DAB/Nickel. Cerebellar axotrophin immunoreactivity is detected in neurons of the molecular layer (mo), Purkinje cell layer (pu) and granule cell layer (gr). Stellate neurons in the molecular layer and Purkinje cells are strongly labeled, whereas the granule cell layer exhibits a diffuse staining. Tau knock-out mice reveal a stronger nuclear axotrophin staining than mice expressing the human tau isoforms (human tau gene-transgenic mice, scale bar: 30 μm). The insets show that increased axotrophin staining in tau knock-out mice is due to a stronger axotrophin accumulation in the nucleus (scale bar 6 μm). (B) Semi-quantitative densitometric analysis of cytoplasmic and nuclear axotrophin immunoreactivity. There is a significant increase in nuclear axotrophin localization due to the absence of human tau expression in Mapt knock-out brains (Mann–Whitney U-test, p ≤ 0.05, n = 3).