Fig. 6.

Layer IV spiny neurons show direct barrel-to-barrel interactions. Topographic maps of excitatory and inhibitory synaptic inputs onto a layer IV spiny stellate cell (a) and a pyramidal cell (b). Insets show the enlarged cortical area within the slice (white frame). Action potential firing patterns on injection of a suprathreshold depolarizing current pulse at V_rmp are illustrated ina1 and b1. c, EPSPs recorded at V_hold = −60 mV on stimulation of fields in the neighboring barrel at positions indicated in a. Scale bar, 200 μm.