PT  - JOURNAL ARTICLE
AU  - Zhi-Bing You
AU  - Thomas M. Tzschentke
AU  - Ernst Brodin
AU  - Roy A. Wise
TI  - Electrical Stimulation of the Prefrontal Cortex Increases Cholecystokinin, Glutamate, and Dopamine Release in the Nucleus Accumbens: an <em>In Vivo</em> Microdialysis Study in Freely Moving Rats
AID  - 10.1523/JNEUROSCI.18-16-06492.1998
DP  - 1998 Aug 15
TA  - The Journal of Neuroscience
PG  - 6492--6500
VI  - 18
IP  - 16
4099  - http://www.jneurosci.org/content/18/16/6492.short
4100  - http://www.jneurosci.org/content/18/16/6492.full
SO  - J. Neurosci.1998 Aug 15; 18
AB  - In vivo microdialysis, radioimmunoassay, and HPLC with electrochemical or fluorometric detection were used to investigate the release of cholecystokinin (CCK), glutamate (Glu), and dopamine (DA) in nucleus accumbens septi (NAS) as a function of ipsilateral electrical stimulation of medial prefrontal cortex (mPFC). CCK was progressively elevated by mPFC stimulation at 50–200 Hz. Stimulation-induced CCK release was intensity-dependent at 250–700 μA. NAS Glu and DA levels were each elevated by stimulation at 25–400 Hz; the dopamine metabolites DOPAC and homovanillic acid were increased by stimulation at 100–400 Hz. When rats were trained to lever press for mPFC stimulation, the stimulation induced similar elevations of each of the three transmitters to those seen with experimenter-administered stimulation. Perfusion of 1 mm kynurenic acid (Kyn) into either the ventral tegmental area (VTA) or NAS blocked lever pressing for mPFC stimulation. VTA, but not NAS, perfusion of Kyn significantly attenuated the increases in NAS DA levels induced by mPFC stimulation. Kyn did not affect NAS CCK or Glu levels when perfused into either the VTA or NAS. The present results are consistent with histochemical evidence and provide the first in vivoevidence for the existence of a releasable pool of CCK in the NAS originating from the mPFC. Although dopamine is the transmitter most closely linked to reward function, it was CCK that showed frequency-dependent differences in release corresponding most closely to rewarding efficacy of the stimulation. Although not essential for the reward signal itself, coreleased CCK may modulate the impact of the glutamatergic action in this behavior.