Visual Prey Capture in Larval Zebrafish Is Controlled by Identified Reticulospinal Neurons Downstream of the Tectum

MeL neurons in the nMLF project dendrites into the ventral tectum. A projection of confocal images (80 images at 1 μm steps) showing backfilled nMLF neurons (red) and Shh:GFP-expression in RGC axons terminating at the tectum (green). Another retinal ganglion cell arborization field, AF-9, is visible. (AF-9 appears superimposed on the tectum but is in fact ventral to it.) GFP-expressing neurons (green) in the top left of the micrograph belong to the ventral thalamus. MeLc, MeLr, and other nMLF neurons (red) project dendrites into the medioventral region of the deep tectum (arrowheads). RGC axons terminate more superficially and do not overlap with nMLF dendrites, although they appear colocalized in this projection. The diagram to the left indicates the approximate position of the imaged field with respect to the tectum (Tec) and the RS array.