In situ hybridization analysis. Autoradiographs of parasagittal (Upper) and horizontal (Lower) sections of adult mouse brain were hybridized to 35S-labeled oligonucleotides specific for exons 2 (C1), 13 (C5), 21 (C7), and the T1 region (exon 28) of the gephyrin mRNA. Note similar labeling patterns of the C1, C5, and C7 probes.