Fig. 1.

Acetylcholine depolarizes layer V pyramidal neurons of rat medial prefrontal cortex. A, Toptrace, Pressure application of acetylcholine depolarized this neuron and triggered a period of sustained spiking activity.Bottom trace, Two minutes after recovery, a second application of acetylcholine induced a comparable effect. B, After bath administration of 100 nm atropine, the acetylcholine response was almost completely inhibited. These recordings were obtained using potassium methylsulfate-based intracellular solution containing 20 μmEGTA.