Fig. 3

The androgen receptor (AR) is expressed in astrocytes and neurons. a Double labeling of AR and GFAP on spinal cord cross sections of castrated males at 30 dpl. Cell nuclei were counterstained in blue with DAPI. Within the LPC lesion, delimited by the dotted line, AR and GFAP staining were very low in males receiving an empty implant (LPC), but AR and GFAP colocalized in males receiving an implant filled with T (LPC + T). Yellow asterisk indicates a motoneuron (b–d). The enlargement in the LPC + T panel shows AR expression in GFAP⁺ cells. AMD3100 blocked the T-dependent appearance and colocalization of AR and GFAP inside the lesion. AR immunostaining remained present around the lesion after the apparition of AR⁺ astrocytes in the lesion (c). e–g Colocalization of AR and NeuN⁺, marking spinal motoneurons. T treatment was associated with the translocation of neuronal AR into the nucleus and the appearance of nuclear AR immunostaining was not prevented by AMD3100 (e, f). AR immunostaining in neurons was not affected by treatment with T and AMD3100 (g). Data are presented as means ± S.E.M. (one-way ANOVA with Tukey's multiple comparisons tests). Asterisks mark significant differences. ***P < 0.001, **P < 0.01. Scale bars: 20 µm (a) and 10 µm (e)