Model files from the manuscript: Augustin, H, Zylbertal, A and Partridge L, "A computational model of the escape latency in the Giant Fiber System of D. melanogaster" (preprint) The file gfs_param_scan_conductances.py reproduces the protocol used in Fig. 3 of the article by calling the module gfpn.py. Questions on how to use this model should be directed to asaph.zylbertal at mail.huji.ac.il Synopsis: The Giant Fiber System (GFS) is a multi-component neuronal pathway mediating rapid escape response in adult fruit-fly Drosophila melanogaster, usually in the face of a threatening visual stimulus. Two branches of the circuit promote the response by stimulating an escape jump followed by flight initiation. Our recent work demonstrated an age-associated decline in the speed of signal propagation through the circuit, likely due to the diminishing number of gap junctions between its components in ageing flies. In this work, we generated a realistic conductance-based computational model of the GFS that recapitulates our experimental results and identifies some of the critical anatomical and physiological components governing the response latency of the circuit. Overall, anatomical properties of the GFS neurons have a stronger impact on the transmission speed compared to the effect of changes in neuronal membrane conductance densities. Our model and provides testable predictions for improving the circuit’s performance in ageing animals by means of experimental interventions. This example protocol plots the GFS latency as a function of gap junction conductance and: 1) Transient voltage gated sodium conductance 2) Voltage gated potassium conductance 3) Leak conductance Example use: Extract the archive, run nrnivmodl in the channels directory (linux/unix) or mknrndll (mswin or mac os x) (see http://senselab.med.yale.edu/ModelDB/NEURON_DwnldGuide.html for more help) to compile the channels, and run the file gfs_param_scan_conductances.py. After a while, it will plot the latency maps.