TY - JOUR
T1 - Acute and chronic dopamine receptor stimulation modulates AMPA receptor trafficking in nucleus accumbens neurons cocultured with prefrontal cortex neurons
AU - Sun, Xiu
AU - Milovanovic, Michael
AU - Zhao, Yun
AU - Wolf, Marina E.
PY - 2008/4/16
Y1 - 2008/4/16
N2 - Postsynaptic interactions between dopamine (DA) and glutamate receptors in the nucleus accumbens (NAc) are critical for addiction. To determine the effect of acute and repeated DA receptor stimulation on AMPA receptor (AMPAR) synaptic targeting in medium spiny NAc neurons, we developed a model system consisting of rat NAc neurons cocultured with prefrontal cortex neurons from enhanced green fluorescent protein-expressing mice. Cortical neurons restore excitatory input onto NAc neurons but are distinguishable based on fluorescence. First, we showed that brief D1-like agonist exposure increased AMPAR insertion onto extrasynaptic regions of NAc neuronal processes through a mechanism requiring protein kinase A. This facilitated the Ca2+/calmodulin dependent protein kinase II (CaMKII)-dependent synaptic incorporation of AMPARs in response to subsequent NMDA receptor (NMDAR) stimulation. Through this mechanism, DA may promote reward- and drug-related plasticity in the NAc. Then, to model effects of repeated in vivo cocaine exposure, we treated cocultures with DA (1μM, 30 min) on days 7, 9, and 11 in culture. On day 15, NAc neurons exhibited increased synaptic AMPAR levels. This was associated with CaMKII activation and was blocked by the CaMKII inhibitor KN-93 (N-[2-[N-(4- chlorocinnamyl)-N-methylaminomethyl] phenyl]-N-(2-hydroxyethyl)-4- methoxybenzenesulfonamide phosphate salt). Furthermore, D1-like agonist exposure on day 15 no longer increased AMPAR surface expression. This refractoriness was associated with decreased D1 receptor surface expression. NMDAR surface expression was not altered by acute or repeated DA receptor stimulation. These results suggest that (1) after repeated DA treatment, NAc neurons are more responsive to glutamate inputs but D 1-like receptor regulation of plasticity is impaired, and (2) NAc/prefrontal cortex cocultures are useful for studying dopamine-induced neuroadaptations.
AB - Postsynaptic interactions between dopamine (DA) and glutamate receptors in the nucleus accumbens (NAc) are critical for addiction. To determine the effect of acute and repeated DA receptor stimulation on AMPA receptor (AMPAR) synaptic targeting in medium spiny NAc neurons, we developed a model system consisting of rat NAc neurons cocultured with prefrontal cortex neurons from enhanced green fluorescent protein-expressing mice. Cortical neurons restore excitatory input onto NAc neurons but are distinguishable based on fluorescence. First, we showed that brief D1-like agonist exposure increased AMPAR insertion onto extrasynaptic regions of NAc neuronal processes through a mechanism requiring protein kinase A. This facilitated the Ca2+/calmodulin dependent protein kinase II (CaMKII)-dependent synaptic incorporation of AMPARs in response to subsequent NMDA receptor (NMDAR) stimulation. Through this mechanism, DA may promote reward- and drug-related plasticity in the NAc. Then, to model effects of repeated in vivo cocaine exposure, we treated cocultures with DA (1μM, 30 min) on days 7, 9, and 11 in culture. On day 15, NAc neurons exhibited increased synaptic AMPAR levels. This was associated with CaMKII activation and was blocked by the CaMKII inhibitor KN-93 (N-[2-[N-(4- chlorocinnamyl)-N-methylaminomethyl] phenyl]-N-(2-hydroxyethyl)-4- methoxybenzenesulfonamide phosphate salt). Furthermore, D1-like agonist exposure on day 15 no longer increased AMPAR surface expression. This refractoriness was associated with decreased D1 receptor surface expression. NMDAR surface expression was not altered by acute or repeated DA receptor stimulation. These results suggest that (1) after repeated DA treatment, NAc neurons are more responsive to glutamate inputs but D 1-like receptor regulation of plasticity is impaired, and (2) NAc/prefrontal cortex cocultures are useful for studying dopamine-induced neuroadaptations.
KW - CaMKII
KW - D receptor
KW - GluR1
KW - LTP
KW - Plasticity
KW - Protein kinase A
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U2 - 10.1523/JNEUROSCI.0258-08.2008
DO - 10.1523/JNEUROSCI.0258-08.2008
M3 - Article
C2 - 18417701
AN - SCOPUS:42949146579
SN - 0270-6474
VL - 28
SP - 4216
EP - 4230
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 16
ER -