Figure 13.
Cajal-Retzius cells drive feedforward GABAergic input to pyramidal cells. A, Example of an interneuron firing following blue light stimulation. Anatomical reconstruction (left); gray area labels stratum lacunosum-moleculare. Red, Somatodendritic arborization; black, axon. Right, Action potentials triggered by light stimulation (five sweeps superimposed). B, Light-evoked long-latency currents recorded in pyramidal cells with high (135 mm; left, Vh = −60 mV) or low intracellular [Cl−] (10 mm; right, Vh = 0 mV) pipette solutions (four sweeps superimposed). Notice that these long-latency responses are fully abolished by gabazine (gbz; 12.5 μm). C, GABAergic long-latency currents evoked by light flashes are the result of a feedforward circuit and are sensitive to NBQX (20 μm; Vh = 0 mV). Two examples are shown in the left and right panels, respectively (four sweeps superimposed).