Colocalization of Dyrk1A and Arip4 in hippocampal pyramidal neurons. Conventional fluorescence microscopy (A, B, and G) and confocal laser scanning microscopy (C to F) images show the same pyramidal neuron in an organotypic hippocampal explant transfected with plasmids encoding ECFP-Dyrk1A, EYFP-Arip4, and DsRed2 and stained with DAPI. Corresponding images of the same region were obtained to visualize ECFP-Dyrk1A (green) and EYFP-Arip4 (red), the cell body of transfected neurons (labeled with DsRed2; red), and the nuclei of all cells (DAPI; blue). Merged images of ECFP-Dyrk1A and EYFP-Arip4 were generated to show the colocalization of Dyrk1A and Arip4 (yellow; F). To visualize the nucleus and the distribution of the chromatin, the DAPI image (G) was superimposed on the confocal ECFP-Dyrk and EYFP-Arip4 image (F) to generate the image in panel C. Asterisks in panels F and G indicate corresponding locations. Open arrowheads (ECFP-Dyrk1A) and filled arrowheads (EYFP-Arip4) indicate speckles containing only Dyrk1A and only Arip4, respectively. Scale bars: A and B, 25 μm; C, 5 μm; D to G, 5 μm (bar shown only in panel D).