Visualizing and Measuring Dendrite Arborization in Drosophila Somatosensory Neurons

Dendrites of neurons receive synaptic or sensory inputs and are important sites of neuronal computation. The morphological features of dendrites not only are hallmarks of the neuronal type but also largely determine a neuron's function. Thus, dendrite morphogenesis has been a subject of intensive study in neuroscience. Quantification of dendritic morphology, which is required for accurate assessment of phenotypes, can often be a challenging task, especially for complex neurons. Because manual tracing of dendritic branches is labor-intensive and time-consuming, automated or semiautomated methods are required for efficient analysis of a large number of samples. A popular in vivo model system for studying the mechanisms of dendrite morphogenesis is dendritic arborization (da) neurons in the Drosophila larval peripheral nervous system. In this chapter, we introduce methods for visualizing and measuring the dendritic arbors of these neurons. We begin with an introduction of da neurons and an overview of the methods that have been used for measuring da neuron dendrites. We then discuss the techniques and detailed steps of neuron visualization and image acquisition. Finally, we provide example steps for dendrite tracing and measurement.