Fig. 5.
Lateral inhibition in the PGN can activate GABAB receptors. A, Local activation of the PGN with glutamate (glu) evokes IPSPs and a spindle wave in this PGN neuron. B, Local application of bicuculline (400 μm in micropipette) reduces but does not completely block this evoked IPSP. C, Local application of CGP35348 (2 mm in micropipette) blocks the residual IPSP, indicating that it was mediated by GABAB receptors.D, Recovery of the evoked IPSPs after washing out the GABA receptor blockers. In A–D, the top traces show overlapped four to five different applications of glutamate, whereas the bottom traces represent the average. Action potentials have been truncated. The membrane potential of this PGN cell varied between applications in control and recovery owing to the bi-stable nature of PGN cell activity.