Expression of roboΔC.Scer\UAS in the giant fiber system, under the control of Scer\GAL4A307 results in axonal midline crossing. The latency of these axons, a measure of synaptic function, is slightly increased in comparison with that of control flies. Expression of roboΔC.Scer\UAS in the tergotrochanteral motor neurons, under the control of Scer\GAL4shakB.lethal.4.1 has no effect on the dendritic projection or the function of the synapse.