A, D and E, network burst amplitudes showing the effect of PD168077 (20 μm) in PFC pyramidal neurons of hD4.7‐infected, D4R knockout mice injected with MPH or saline control. B and F, representative network bursts in the absence or presence of PD168077 in hD4.7‐expressing neurons with MPH or saline injection. C and G, percentage reduction of the amplitude of network bursts by hD4.7 activation in PFC neurons from MPH‐ or saline‐injected mice. Cell membranes were held at −70 mV (A to C) or −20 mV (D to G). *P < 0.01, t test, hD4.7‐MPH vs. hD4.7‐saline.