(e) Quantification of the average number of rhabdomeres per ommatidium in Huntington's disease flies with ebselen or vehicle (DMSO; n = 10) treatment at day 7 after eclosion and in newly emerged day 0 adult flies (untreated control; n = 10). Significant treatment effects were observed, both with the 100 μM (**P 0.01; n = 9) and 300 μM (***P 0.001; n = 9) doses of ebselen. All data are shown as the mean ± s.e.m. 