Figure 6: photos of substantia nigra of animals treated with selegiline where (5 a,b) are treated with selegiline only so that (5a) showed mild neurodegeneration and gliosis arrow (H&E X200) (5b) showed ballooning of neuronal cells with shorting of dendritic branches and Lewy bodies detected in both extra-neuronal cells arrow (H&E X400) while (6a,b) are those combined with low dose metformin where (6 a) showed degenerative changes of neuronal cells arrow (H&E X200),(6 b) swelling of neuronal cells with gliosis (H&EX400) and (7a,b) are those combined with high dose metformin in which (7a) showed neurodegenerative changes characterized by neuronal swelling and shorting of dendritic branches arrow (H&EX200) (7b) focal hemorrhagic area (H&EX200).