A Method for Chronically Implanting Stimulat- Ing Electrodes into the Brains of Locusts, and Some Results of Stimulation

The results of electrical stimulation of the insect supraoesophageal ganglion have been reported by Huber (i960A and previous works) from acute preparations of Gryllus. The present study is centred around a technique of cerebral stimulation which augments this work in two ways: first, by using a different species, Schistocerca gregaria, the desert locust, and secondly by providing a method of stimulating virtually unrestrained insects through chronically implanted electrodes. Huber's method has been especially valuable for studying such functions as respiration, for the movements of spiracles, etc., can only be observed accurately in the restrained animal; the method described below, which allows a free-moving animal to be tested in a familiar environment on many different occasions, is more suited to behavioural studies.