The impact of manganese on neurotransmitter systems

Background: Manganese (Mn) is a metal ubiquitously present in nature and essential for many living organisms. As a trace element, it is required in small amounts for the proper functioning of several important enzymes, and reports of Mn deficiency are indeed rare. Methods: This mini-review will cover aspects of Mn toxicokinetics and its impact on brain neurotransmission, as well as its Janus-faced effects on humans and other animal's health. Results: The estimated safe upper limit of intracellular Mn for physiological function is in anarrow range of 20-53 mu M.Therefore, intake of higher levels of Mn and the outcomes, especially to the nervous system, have been well documented. Conclusion: The metal affects mostly the brain by accumulating in specific areas, altering cognitive functions and locomotion, thus severely impacting the health of the exposed organisms.