Differential effect of DHB on mitochondrial activity. (A) Representative examples of ATP synthesis measurements in spinal cord expressed as relative luminescence units (R.L.U.). (B) The rate of ATP synthesis in SOD1-G93A mitochondria purified from spinal cord (data = mean ± se; repeated measures, n = 9; ** - p < 0.001). (C) Effect of DHB on rotenone mediated cell viability. Primary mixed spinal cord neurons from SOD1-G93A mice were cultured in the presence or absence of DHB (5 mM) and exposed to mitochondrial Complex I inhibitor rotenone (data = mean ± se; Rot: n = 4, Rot+DHB: n = 4; *** - p < 0.001, Rot vs. Rot+DHB). (D) Absence of specific inhibition of DHB in SOD1-G93A cultures exposed to mitochondrial Complex II inhibitor malonate (data = mean ± se; Mal: n = 4, Mal+DHB: n = 4).