Fig. 3. Nd1-L mRNA content is decreased in TLS-null hippocampal neurons. (A) Cell in situ hybridization for detection of Nd1-L and ß-actin mRNA. Primary cultures of mouse hippocampal neurons were prepared from wild-type and TLS-null mouse embryos. At 23 DIV, the cells were treated with 50 mM DHPG for 60 minutes or left untreated as a control. The amount of Nd1-L mRNA in dendrites is increased by DHPG treatment. However, it is much lower in TLS-null dendrites and is not increased even after DHPG treatment. Bar, 5 µm. (B) Quantitative representation of the cell in situ hybridization in A. (C) Lower magnification of cell in situ hybridization data. Nd1-L mRNA is unevenly distributed in dendrites (arrowheads) and forms clusters at dendritic branching points (arrows). ß-actin mRNA is evenly distributed in dendrites (right). Bars, left, 20 µm, right, 10 µm. Inset in the middle panel shows the DIC image.