Parkinson’s Disease (PD) is a late-onset and progres­sive neurodegenerative disorder. The main pathological characteristics of familial and sporadic cases is degenera­tion of dopaminergic neurons in substantia nigra pars com­pacta and intracellular protein aggregates (Lewy bodies) in surviving neurons. Six different genes defined in famil­ial cases and the functions of the proteins they encode, revealed that the cellular abnormalities primarily affect the ubiquitin-proteasome system. Oxidative stress and various toxins are also important in development of the disease. Recent studies have shown that apoptosis plays an impor­tant role in the molecular pathology of dopaminergic neu­rons. Although cell culture and animal models of PD have shown that apoptotic proteins have a major role in cell death, apoptosis may not be the correct term if it is used in its narrow sense. Detailed molecular analyses on possible genetic and/or environmental factors known to trigger cell death in PD, and the effect of these factors on the activa­tion of programmed cell death, would reveal further details of the complex cell death mechanism in PD.

      Key words: Parkinson’s Disease (PD); Programmed Cell Death; Apoptosis