The role of lithium in neurodegenerative diseases: new registries for old actors

Introduction. Lithium has been used for more than one century in medicine. Currently, it is used effectively in acute phase treatment and in the prevention of manic-depressive symptoms of patients with bipolar disorder. Lithium acts by inhibiting a protein-kinase called glycogen synthase kinase 3 (GSK3) that has important actions on the intracellular signal transmission by protein phosphorylation. Method: A review has been made of the studies conducted in vivo and in vitro on the utility of lithium in animal models of neurodegenerative disease and its efficacy in studies performed in humans. Development. Research on lithium on GSK-3 inhibition in animal models of disease with aggregates of hyperphosphorylated protein tau and Alzheimer's disease has provided promising results. Inhibition of this enzyme also seems to have a neuroprotector effect in other neurodegenerative disease models such as amyotrophic lateral sclerosis, spinocerebellar ataxia type I and Huntington's disease. There is indirect evidence in humans on a possible neuroprotector effect in chronic patients with bipolar disorder and on slow down of the progression of the disease in patients with amyotrophic lateral sclerosis. Conclusions. Lithium, and in a more extensive way, GSK-3 inhibitors, are proposed as a new drug generation with potential action on the progression of different neurodegenerative diseases, especially those related with abnormal aggregation of the protein tau.