Resolution of complex neuronal arrangements in the blowfly visual system using triple fluorescence staining

Consecutive application of the fluorescent dyes, Texas Red and Lucifer Yellow, followed by nuclear staining with Bisbenzimide, reveals spatial relationships between individual neurons and relationships between their cell bodies and the perikaryal rind. The method is particularly useful for light-microscopical studies of complex interrelationships between identified neurons. The method has specific advantages over intraneuropil staining with cobalt or with HRP. These advantages are: simplicity, speed, information content, and aesthetic considerations.