Effects of subchronic lithium treatment on levels of BDNF, Bcl-2 and phospho-CREB in the rat hippocampus.

Although it has been proposed that exposure to lithium up-regulates brain-derived neurotrophic factor (BDNF), B-cell leukaemia/lymphoma 2 protein (Bcl-2) and cyclic AMP-response element-binding protein (CREB), and these molecules are involved in the neuroplastic actions and clinical efficacy of the drug, the several lines of evidence suggest that the lithium-induced up-regulation of these molecules has not been consistently confirmed. Few studies have examined the effects of lithium exposure on the regulation of these molecules in the dentate gyrus (DG) and area CA1 in the hippocampus. We examined the effects of subchronic lithium treatment on the levels of BDNF, Bcl-2 and phosphorylated CREB in the DG and area CA1. We administered LiCl intraperitoneally (1 mEq/kg per day) to adult rats for 14 days, killed animals in 24 hr after the last administration of the drug, and determined the tissue levels of BDNF, Bcl-2 and pCREB in the DG and area CA1. Subchronic lithium treatment for 14 days did not significantly alter the levels of BDNF, Bcl-2 or phosphorylated CREB in the DG and area CA1 in the hippocampus. This study indicates that the lithium-induced up-regulation of these molecules may be various depending on the duration of lithium exposure and particular brain regions exposed to the drug.