'Photo-degeneration' of neurones after extracellular dye application

Irradiation in the presence of a dye applied to the extracellular space was found to trigger neuronal degeneration in fly photoreceptor neurones. This phenomenon endowed the selected cells with a dark and fine-grained label such that they could be traced and scrutinized for synaptic specializations. It also initiated their phagocytotic removal from the neural network. Various states of degeneration fitting classical descriptions could be achieved by acting upon the light dose. The phenomenon seems to rely on photosensitization of the cell by the dye. The simplicity and precision with which this phenomenon can be induced makes 'photo-degeneration' an exciting prospective tool for combined anatomical and physiological studies on (natural) neural networks and may provide a new line of medical applications.