Figure 1:
Camptothecin induces apoptosis in ex vivo nerve tissue. Fluorescence micrographs of tissue labeled using anti-active caspase 3 (A-D) and TUNEL (E-H) in red. Staining is shown for untreated fresh nerves (A, E) and nerves treated with camptothecin for one day in vitro at 0 μM (B, F), 5 μM (C, G), and 10 μM (D, H). Nuclei are counterstained with DAPI (blue). Scale bar is 200 μm. Processing and staining was repeated at least three times per group. (I-K) Images from a longitudinal section of a drug-treated nerve, imaged at 20X and enlarged to show detail. Arrows indicate colocalization of cleaved caspase-3 and neurofilament, suggestive of axonal staining. Arrowheads indicate cleaved caspase-3 staining associated with a nucleus but not with neurofilament, suggesting non-neuronal staining such as fibroblasts or Schwann cells. Scale bar is 50 μm.