The reticular theory predominated until the 1890s when Ramon y Cajal brought forth his neuron doctrine of synaptic junctions, which in essence replaced the reticular theory.

Gerlach was one of the first physicians to use photomicrography for medical research. In 1863, he published a handbook titled Die Photographie als Hilfsmittel mikroskopischer Forschung (Engl. "Photography as a tool