Neuroprotective effects of DBH on spinal cord motor neurons. (A) Effect of DHB on rotenone mediated toxicity. Primary spinal cord neurons from SOD1-G93A mice were cultured in the presence or absence of DHB (5 mM) and exposed to rotenone and cell toxicity measured by LDH activity released in the culture media expressed as a percentage of control (data = mean ± se; Rot: n = 4, Rot+DHB: n = 4; ** - p < 0.01, Rot vs. Rot+DHB). (B) Absence of neuroprotection of DHB in SOD1-G93A cultures exposed to malonate expressed as a percentage of control (data = mean ± se; Mal: n = 4, Mal+DHB: n = 4). (C) Photomicrographs of representative staining of motor neurons using SMI-32 antibody in control (top), rotenone (middle) and rotenone and DHB (bottom) treated spinal cord cultures. Motor neurons are SMI32 positive and characterized by their large cell bodies and numerous dendrites. (D) The effect of DHB on chronic mitochondrial toxicity by rotenone. Spinal cords neurons from SOD1-G93A were cultured in the presence or absence of DHB (5 mM) and treated with rotenone (3 nM) (data = mean ± se; Control: n = 4, Rotenone: n = 4, Rot+DHB: n = 4; # - p = 0.041, Rotenone vs. Rot+DHB; ** - p = 0.004, Rotenone vs. Control).