Projection area of ingrowing photoreceptors
The transparent contour describes the area into which photoreceptors project. The actual lamina neuropil is only a very thin layer in the larval stage. The lamina surrounds the inner cell plug, which derives from the IOA and contributes e.g. to T&C cells. The lamina itself is proliferated from the outer optic anlagen, which is not shown in this model.
The Bolwig nerve connects the larval photoreceptors with the larval optic neuropil, which is situated at the base of the medulla.
The inner optic anlage is targeted by strong expression in Mz1369. It is the proliferation region which creates neurons of the lobula and proximal medulla.
Part of the cells that make up the proximal medulla neuropil are derived from the inner optic anlagen.
The cells that build the lobula neuropil derive from the inner optic anlagen.
These cells are derived from the inner optic anlage. They create the population of T&C cells.