Figure 2.

Dlxi12b-labeled PFC neurons projecting to ventral striatum exclusively release GABA. A, Experimental design: Dlxi12b–Cre mice were injected with AAV–DIO–ChR2–EYFP into the mPFC. Recordings were made from NAcc neurons during optogenetic stimulation. B, Images of ChR2⁺ GABAergic fibers projecting from mPFC within NAcc at low and high power (top and bottom rows; scale bars, 60 and 15 μm, respectively). C, D, Long-range Dlxi12b-labeled projections from mPFC release GABA. Light-evoked outward currents were inconsistently affected by CNQX/AP-5 but completely blocked by adding GBZ (n = 7 cells). E, F, Dlxi12b-labeled fibers do not release glutamate because GBZ alone completely blocked currents recorded at −70 and +10 mV (n = 4 cells). cont, Control; DIC, differential interference contrast; VC, voltage clamp.