Figure 5: photos of substantia nigra of animals treated with metformin low and high dose where 3 (a,b) are that of low dose in which (3a) showed neuronal degeneration arrow (H&EX200). (3b) neuronal necrosis with extra-cellular Lewy bodies arrow while 4(a,b) that treated with high dose in which (4a) showed mild degenerative changes of neuronal cells arrow (H&EX200) (4b) Swelling of neuronal cells with shorting of dendritic branches extra-cellular Lewy bodies arrow (H&E X400).