(a). Left panel, in situ hybridization performed using an antisense riboprobe specific for PSD–95 mRNA (red), combined with an immunofluorescence for FMRP (green) on wildtype (WT) hippocampal cultures (DIV 10). Merged image and a merged magnification are also shown (yellow). Right panel, in situ hybridization for PSD–95 in FMR1 knockout hippocampal cultures (top) and magnification (bottow). (b). Upper panels. Bright field. In situ hybridization performed using an antisense riboprobe specific for the cell body-specific α–Tubulin mRNA (red), combined with an immunofluorescence for FMRP (green) on hippocampal cultures (DIV 10). Lower panels. Bright field (left panel). In situ hybridization performed using an antisense riboprobe specific for the dendritically localized α–CaMKII mRNA (red, middle panel), combined with an immunofluorescence for FMRP (green, right panel) on hippocampal cultures (DIV 10).