Fig. 2. Quantitative analysis of status epilepticus-induced changes in expression of metabotropic glutamate receptor mRNAs (mGluR1–5) in hippocampus of pup rats. Data indicate the mean densities of autoradiographic films for in situhybridization of mGluR1–5 in CA1, CA3, and DG at the level of the dorsal hippocampus at 3 hr (A) 24 hr (B) and 30 d (C) after the onset of status epilepticus in P10 pup rats. A, At 3 hr after the onset of status epilepticus, mGluR1–5 expression did not differ significantly from that of control animals. B, At 24 hr after the onset of status epilepticus, mGluR2 mRNA expression was significantly decreased in the DG granule cell layer of status epilepticus pups relative to that of controls; mGluR4 mRNA expression was significantly increased in the CA3 pyramidal cell layer.C, By 30 d after the onset of status epilepticus, mGluR2 mRNA expression in DG and mGluR4 expression in CA3 were at control values. mGluR1, mGluR3, and mGluR5 mRNA expression levels were unchanged at all times examined. Error bars indicate SE (n = 6). *Statistical significance at a level ofp < 0.01, as determined by the Student’s unpairedt test. Density readings for mGluR1–5 mRNAs were made over the depth of the cell body layer of each subfield, CA1, CA3, and DG, at the level of the dorsal hippocampus. Data indicate the mean densities of autoradiographic films for a given subfield taken from a minimum of three consecutive sections of each of six animals per time point. Averaged film densities corresponding to expression of mGluR1–5 mRNAs for each hippocampal subfield in control rats were corrected for film backgrounds and are defined as 100%. SEMs for a given probe and subfield at each time point were <5%.