This is a graph of the change in ACh release over 13 fifteen minute increments. For the first four collections, artificial cerebrospinal fluid is pumped through the microdialysis probes, to determine baseline ACh release. From the fourth to the eighth interval, 100 uM (Micromolar) SCH-23390 and 150 um NMDA are infused into the nucleus accumbens. NMDA usually causes a robust increase in cortical ACh release, yet the data shows SCH-23390 attenuates the NMDA-mediated increase. The black line is the change in cortical ACh release with just NMDA, and the red line shows the effective attenuation of cortical ACh release by SCH-23390, a D1 antagonist.
SCH-23390 attenuated the NMDA-mediated increase in ACh release, suggesting that dopamine, at D1 receptors, is contributing to NMDA's ability to stimulate cortical ACh release.