TY - JOUR T1 - Dopamine Neurons Mediate a Fast Excitatory Signal via Their Glutamatergic Synapses JF - The Journal of Neuroscience JO - J. Neurosci. SP - 972 LP - 981 DO - 10.1523/JNEUROSCI.4317-03.2004 VL - 24 IS - 4 AU - Nao Chuhma AU - Hui Zhang AU - Justine Masson AU - Xiaoxi Zhuang AU - David Sulzer AU - René Hen AU - Stephen Rayport Y1 - 2004/01/28 UR - http://www.jneurosci.org/content/24/4/972.abstract N2 - Dopamine neurons are thought to convey a fast, incentive salience signal, faster than can be mediated by dopamine. A resolution of this paradox may be that midbrain dopamine neurons exert fast excitatory actions. Using transgenic mice with fluorescent dopamine neurons, in which the axonal projections of the neurons are visible, we made horizontal brain slices encompassing the mesoaccumbens dopamine projection. Focal extracellular stimulation of dopamine neurons in the ventral tegmental area evoked dopamine release and early monosynaptic and late polysynaptic excitatory responses in postsynaptic nucleus accumbens neurons. Local superfusion of the ventral tegmental area with glutamate, which should activate dopamine neurons selectively, produced an increase in excitatory synaptic events. Local superfusion of the ventral tegmental area with the D2 agonist quinpirole, which should increase the threshold for dopamine neuron activation, inhibited the early response. So dopamine neurons make glutamatergic synaptic connections to accumbens neurons. We propose that dopamine neuron glutamatergic transmission may be the initial component of the incentive salience signal. ER -