SUSTAINED LONG-TERM POTENTIATION AND ANXIETY IN MICE LACKING THE MAS PROTOONCOGENE

The Mas protooncogene is a maternally imprinted gene encoding an orpha n G protein-coupled receptor expressed mainly in forebrain and testis, Here, we provide evidence for a function of Mas in the central nervou s system. Targeted disruption of the Mas protooncogene leads to an inc reased durability of long term potentiation in the dentate gyrus, with out affecting hippocampal morphology, basal synaptic transmission, and presynaptic function. In addition, Mas(-/-) mice show alterations in the onset of depotentiation, The permissive influence of Mas ablation on hippocampal synaptic plasticity is paralleled by behavioral changes . While spatial learning in the Morris water maze is not significantly influenced, Mas-deficient animals display an increased anxiety as ass essed in the elevated-plus maze. Thus, Mas is an important modulating factor in the electrophysiology of the hippocampus and is involved in behavioral pathways in the adult brain.