Recurrent circuits in layer II of medial entorhinal cortex in control and epileptic animals evaluated with laser-scanning photostimulation. A, Maps depict composite amplitudes of EPSCs (holding potential, −70 mV) occurring in measurement windows 10–30 ms after photostimulation. Traces under maps are typical responses, and corresponding photostimulation sites are indicated by filled yellow circles. B, Maps from the same cells showing composite amplitudes of IPSCs (holding potential, 0 mV) occurring in measurement windows 10–110 ms after photostimulation. Traces under maps are typical responses. C, Neurons from which data in A and B were obtained (red, biocytin; green, NeuN immunoreactivity; L I-II, layers I-II). The yellow arrowhead indicates a cell from epileptic rat whose responses are shown above.