Making Memories Last

Abstract

Pharmacological and biochemical analyses reveal that dopamine determines the duration of fear memory storage. How can memory traces persist over days or weeks, despite the short-lived nature and rapid turnover of their molecular substrates? It has recently been reported that, in order to persist, an otherwise rapidly forgotten long-term memory requires BDNF (brain-derived neurotrophic factor) expression in the hippocampus 12 hours after training. Rossato et al. now show that this mechanism is gated into action by activation of the ventral tegmental area acting upon dopamine D1 receptors in the hippocampus. Time-limited N-methyl-D-aspartate receptor–dependent activity in the ventral tegmental area–hippocampal circuitry underlies the delayed increase in BDNF levels in the hippocampus 12 hours after inhibitory avoidance, a hippocampus-dependent form of learning. J. I. Rossato, L. R. M. Bevilaqua, I. Izquierdo, J. H. Medina, M. Cammarota, Dopamine controls persistence of long-term memory storage. Science 325, 1017–1020 (2009). [Abstract] [Full Text]