Ishikawa Akinori, Ambroggi Frederic, Nicola Saleem M, Fields Howard L
Ernest Gallo Clinic and Research Center and Department of Neurology, University of California, San Francisco, Emeryville, California 94608, USA.
J Neurosci. 2008 May 7;28(19):5088-98. doi: 10.1523/JNEUROSCI.0253-08.2008.
Cue-elicited phasic changes in firing of nucleus accumbens (NAc) neurons can facilitate reward-seeking behavior. Here, we test the hypothesis that the medial prefrontal cortex (mPFC), which sends a dense glutamatergic projection to the NAc core, contributes to NAc neuronal firing responses to reward-predictive cues. Rats trained to perform an operant response to a cue for sucrose were implanted with recording electrodes in the core of the NAc and microinjection cannulas in the dorsal mPFC (dmPFC). The cue-evoked firing of NAc neurons was reduced by bilateral injection of GABA(A) and GABA(B) agonists into the dmPFC concomitant with loss of behavioral responding to the cue. In addition, unilateral dmPFC inactivation reduced ipsilateral cue excitations and contralateral cue inhibitions. These findings indicate that cue-evoked excitations and inhibitions of NAc core neurons depend on dmPFC projections to the NAc and that these phasic changes contribute to the behavioral response to reward-predictive cues.
线索诱发的伏隔核（NAc）神经元放电的相位变化可促进奖赏寻求行为。在此，我们检验以下假设：向NAc核心发送密集谷氨酸能投射的内侧前额叶皮质（mPFC），有助于NAc神经元对奖赏预测线索的放电反应。训练大鼠对蔗糖线索做出操作性反应，将记录电极植入NAc核心，并将微量注射套管植入背侧mPFC（dmPFC）。向dmPFC双侧注射GABA(A)和GABA(B)激动剂会减少NAc神经元的线索诱发放电，同时对线索的行为反应丧失。此外，单侧dmPFC失活会减少同侧线索兴奋和对侧线索抑制。这些发现表明，线索诱发的NAc核心神经元兴奋和抑制依赖于dmPFC向NAc的投射，并且这些相位变化有助于对奖赏预测线索的行为反应。
