Figure 1.

Effect of Hsp90 inhibition on neuronal survival. (a) Motor neurons were prepared from 15 days old rat embryos by a combination of gradient centrifugation and immunoaffinity. Pure motor neurons were cultured for 24 h with or without a combination of BDNF, GDNF, and CT-1 previous to incubation with geldanamycin for 24 h before determine viability. Neuron survival was determined by analyzing the imagens of calcein-AM-stained neurons using the Tina software (Trophos) or by counting under phase contrast. The survival between experiments was normalized to the survival of the corresponding control group incubated without geldanamycin. (b) Motor neurons were treated with geldanamycin (0–500 nM) in the presence (TF+GA) or absence of trophic factors (GA) for 24 h. (c) Cells from whole embryo ventral spinal cords (SC), purified motor neuron with trophic factors (motor neurons), and isolated cortical neurons at high (Cortical HD) or low (Cortical LD) density were treated with geldanamycin (0–10 µM) for 24 h. (d) Undifferentiated and differentiated NSC34 cells were treated with geldanamycin (0–100 µM) for 24 h. (e) Motor neurons were cultured with (TF) and without trophic factors (TFD) and incubated with radicicol at the indicate concentrations. For all panels, values represent the mean ± SD of three to five experiments performed by quadruplicate to octuplicate (n ≥ 20 per group). The continuous lines in panels b–e represent the sigmoidal regression curves of the data using the Prism software.