Effect of lithinum administration on RNA metabolism in rat brain

Molecular genetics and heterogeneity in manic depression

Recent research has shown that there are X-linked and possibly chromosome 11-linked forms of manic depression as well as at least one other autosomal form. Segregation analyses of large affected families and the finding of genetic linkage between chromosome specific markers and manic depression mutations provide strong evidence that bipolar as well as unipolar forms of manic depression (MD) within the same family are inherited as a dominant gene disorder. This clarification of the etiology of certain types of depression should bring changed attitudes within psychiatry and may serve to stimulate discussion of the role of evolutionary mechanisms. From a clinical point of view, it has now become possible to determine whether clinical (phenotypic) variation reflects the underlying genotypic heterogeneity of linkage. A preliminary analysis of data from four recent studies shows that there is no clear correlation between such clinical features as the ratio of unipolar to bipolar cases and the genotypic form of manic depression. Further recombinant DNA research, proven to be successful in other genetic diseases, can soon be applied to manic depression. The specific problems posed by manic depression for these techniques are discussed.

The influence of lithium on water binding ability, consistency and macromolecules in the rat brain

Wistar male rats were treated with lithium for 50, 80, and 120 days, respectively. Lithium was added to the diet (40 mmol/kg of diet), the plasma lithium concentration being in the range of 0.55-0.70 mmol/1 of plasma. The treatment caused a significantly more rigid consistency of the brain tissue. The water content and water binding ability in various parts of the brain - measured by a drying course - was unchanged. The content of hexosamine and protein in total brains was significantly decreased (about 10 per cent) after the treatment. The content of chondroitin sulphate in various parts of the brain was unchanged, whereas the content of hyaluronic acid was significantly increased in the cerebellum (25 per cent) and in the thalamic area (20 per cent). The results suggest an influence of lithium on the macromolecules from the extracellular space, causing an alteration of the neuronal function.