Chronically epileptic rats (CERs) demonstrated reduced numbers of interneurons positive for parvalbumin (PV) and neuropeptide Y (NPY) in the dentate gyrus (DG). (A1-A4) illustrate the distribution of PV+ interneurons in a naïve control DG (A1) and a CER (A3). (A2) and (A4) are magnified views of regions from A1 and B1. (B1-B4) illustrate the distribution of PV+ interneurons in the DG of a naïve control rat (B1) and a CER (B3). (B2) and (B4) are magnified views of regions from B1 and B3. The bar charts show that interneurons positive for PV (A5) and NPY (B5) are reduced in number in the DG of CERs. *, p<0.05; ***, p<0.001. Scale bar, A1, A3, B1 and B3, 50 μm; A2, A4, B2 and B4, 25 μm.