Metals in Parkinson's Disease

Abstract

Parkinson's disease (PD) is a neurological disorder that gets worse with time. It happens when dopaminergic neurones in the substantia nigra pars compacta (SNpc) break down. The absence of dopaminergic nerves and a deficiency of dopamine result in motor symptoms marked by rigidity, tremor, and bradykinesia. Trace elements and heavy metals have different effects on the nervous system, both good and bad. Too much exposure to toxic metals like mercury (Hg), lead (Pb), copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), aluminium (Al), arsenic (As), cadmium (Cd), and selenium (Se) can cross the blood-brain barrier and kill dopaminergic neurones. High levels of heavy metals in the brain cause oxidative stress, mitochondrial dysfunction, and the formation of α-synuclein, which damages dopaminergic neurones. There is mounting evidence that heavy metals, which are typically found in trace amounts in the human body, can potentially accumulate to start the production of free radicals and have an impact on basal ganglia signalling.