To test this we used pan-neuronal (nSyb-Gal4) knock-down of the OXPHOS complex IV subunit Surf1, a model for the primary mitochondrial childhood encephalomyelopathy Leigh syndrome, and park25 homozygous mutant flies, a model for familial Parkinson’s disease [36, 40, 41]. The gene discussed is SURF1; the disease is Parkinson disease.