Neurogenetics of Drosophila melanogaster has traditionally been a major theme of many issues of the Journal of Neurogenetics. This special issue has been initiated to honor Erich Buchner, a scientist who has provided a major influence on the field of Drosophila neurogenetics, on the occasion of his 65th birthday, which often represents a time point for retirement. For all who know Erich Buchner, his energetic laboratory, and his active research, it sounds somehow unreasonable to talk about retirement. In fact, this issue has been initiated on the occasion of his formal release from administrative and teaching duties, perhaps giving him the opportunity to focus on his scientific interests in the future.
Erich Buchner, originally a physicist by profession, started his work on Drosophila in the laboratory of Karl Goetz at the Max-Planck-Institute for Biological Cybernetics in Tübingen. In an impressively detailed analysis, Erich Buchner revealed the principles of elementary movement detectors in the fly brain using sophisticated behavioral experiments, e.g., using the elegant “optomotor machine” to study flies walking stationarily on little balls, a technique that has been readopted recently by several laboratories. His second step was likewise influential. Using 2-desoxyglucose mapping, Erich Buchner invented the first optical imaging approach to detect neuronal activity distributed over extended brain regions in Drosophila. In the course of this work, a variety of principles of neuronal coding were revealed that are still valid, e.g., the representation of odors as glomerular activity patterns in the antennal lobe, the role of the central complex as a center for locomotor control, or the identification of motion-sensitive neurons in the Drosophila visual system. After his habilitation Erich Buchner accepted an appointment at the Julius-Maximilians University of Würzburg in the Department of Genetics and Neurobiology. Feeling that the power of Drosophila neurogenetics will provide a strong means to unravel neuronal function on a subcellular level, he concerned himself with the principles of synaptic transmission. By creating an antibody library against synaptic proteins, the Buchner laboratory has identified and functionally characterized a number of synaptic proteins, including the insect synapsin, the chaperone cysteine-string protein, the active zone protein Bruchpilot and the synaptic vesicle protein SAP47. In addition, the Buchner lab was very early in recognizing the power of genetically encoded fluorescence sensor proteins, and was among the first to visualize neuronal activity using calcium-sensitive proteins, a technique that nowadays represents a commonly used tool to functionally dissect neuronal circuits. Finally, applying the recent development of optogenetic techniques to Drosophila has had, as so many techniques, its origins in the Buchner laboratory. A countless number of undergraduate and graduate students, postdocs, and scientific assistants have passed through Erich Buchner's laboratory. We are sure that Erich Buchner's way of teaching science, his care for his lab members and colleagues, and his foresight for future technical and conceptual developments, have had an enormously influential impact on his students and co-workers.
This issue contains articles from scientists who have been working together with Erich Buchner at various research phases or whose work has been influenced substantially by Erich Buchner's work. In accordance with Erich Buchner's broad research interests, the articles cover a wide range of topics, from nervous system development, to synaptic molecules, to neuronal structure and function, to behavioral plasticity. Martin Heisenberg is certainly the most competent person to point down Erich Buchner's major achievements, and we are grateful that he is doing so in a short introduction. Veronica Rodrigues and co-workers report on how Hox genes regulate the morphogenesis of motorneurons. Ulrich Thomas, Oliver Kobler, and Eckart Gundelfinger provide a review on one of Erich Buchner's favorite model systems, the neuromuscular junction, with an emphasis on synaptic scaffold complexes. Konrad Zinsmaier gives insights into the function of the cysteine-string protein that has been discovered in the Buchner laboratory. Carolin Wichmann and Stephan Sigrist focus their article on the presynaptic active zone and discuss how active zone proteins might be involved in synaptic plasticity. KS Krishnan and Riddhi Majumder provide an overview over another aspect of synaptic transmission, namely the process of synaptic vesicle recycling. Tanja Godenschwege and Jana Boerner report a neuroanatomical study and apply the concept of standardizing brain anatomy to the Drosophila ventral nerve cord to investigate the morphology of mutants.
Finally, Mishra Dushyant, Louis Matthieu, and Bertram Gerber report a behavioral study on the increasingly popular model system of the Drosophila larva. By carefully analyzing olfactory behavior they address the question how these animals balance their behavior with respect to generalizing and discriminating between two stimuli. In addition, several articles scheduled to appear in the next issue will also be part of the tribute to Erich Buchner.
Last but not least we would like to express our gratitude to have had and still have the chance to work with Erich Buchner and hope that after his release from many University duties his scientific ideas will continue to fertilize neuroscience in general and the Drosophila neuroscience community in particular.