Dopaminergic Synapse Plasticity

Science Signaling  23 Sep 2008:
Vol. 1, Issue 38, pp. ec332
DOI: 10.1126/scisignal.138ec332

Dopamine neurons, originating in the ventral tegmental area and substantia nigra and projecting to forebrain areas, are essential for the expression of goal-directed behavior. Although dopamine signaling appears to be highly plastic and can be modified by manipulating the contingency between conditioned stimuli and the reward itself, the cellular mechanisms that may underlie this cue-reward learning remain unclear. Stuber et al. used both in vivo electrochemistry and in vitro electrophysiology to study the mechanisms behind cue-reward learning within the mesolimbic dopamine system. They found that dopamine neuron long-term potentiation is associated with the acquisition of motivational properties by the conditioned stimulus. This depends on an N-methyl-D-aspartate-receptor-mediated enhancement of AMPA receptor signaling in these neurons.

G. D. Stuber, M. Klanker, B. de Ridder, M. S. Bowers, R. N. Joosten, M. G. Feenstra, A. Bonci, Reward-predictive cues enhance excitatory synaptic strength onto midbrain dopamine neurons. Science 321, 1690-1692 (2008). [Abstract] [Full Text]