Figure 2. Morphology of neurons in the optic tectum of adult zebrafish.

A. Image of the head of an adult zebrafish following exposure of the left tectum opticum. A schematic drawing of the brain is superimposed on the image of the head of a zebrafish. The region exposed for imaging is marked as the region of interest (ROI). B. Schematic transversal section through the tectum opticum (redrawn after [30]) showing the input layer and the overall cytoarchitecture of some prominent neurons. Areas highlighted in colour indicate where photomicrographs of labelled cells shown in D₁–D₂ are located. C. Schematic three-dimensional view on the tectum. The ROI is highlighted in yellow, while the tectal areas are indicated in blue (BioVis3D). D₁–D₂. Photomicrographs of stained cells. D₁ shows an example of a top view using the in vivo imaging set-up (widefield fluorescence). D₂ is an example of a neuron recovered after the in vivo experiments following routine histological methods. Here a confocal stack of the vibratome sectioned tectum was used to reconstruct the 3D properties of this neuron (BioVis3D). Abbreviations: SM Stratum moleculare; SO Stratum opticum; SFGS Stratum griseum et album superficial; SGC Stratum griseum central; SAC Stratum album central; SPV Stratum periventriculare; OB Olfactory bulb; Tel Telencephalon; TeO Tectum opticum; CCe Corpus Cerebellare; EG Eminentia granularis; MO Medulla oblongata.