This study on the zebrafish optic tectum is a series of four images with magnifications ranging from the SEM block face overview to of the zebrafish head to high magnification (80,000X) showing optic tectum synapse. The first image is a bloc face SEM image at 200x of the epon embedded zebrafish head. The second image is another block face SEM low magnification image of the tectum. The third image is a 60,000X TEM image of a OTO fixation and copper lead en bloc staining of zebrafish optic tectum synapse. This image, the fourth image in the series, is a 80,000X TEM image of a zebrafish optic tectum synapse. Zebrafish 10 dpf Optic Tectum Synapses. Image collected on a JOEL 1230 at 80 kV using a Gatan 967 slow-scan, cooled CCD camera at 80,000X. 70 nm thick section. Microwave processing, osmium tetroxoxide/osmid procedure for enhancing membranes, and copper lead en bloc staining. Procedure for specimen preparation available at http://www.stanford.edu/~redhair/JoAnn_Buchanan.