Analyzing cockroach escape behavior with lesions of individual giant interneurons.

Individual giant interneurons (GIs) in the ventral nerve cord of the cockroach, Periplaneta americana, were lesioned by intracellular injection of proteolytic enzymes (pronase). This was accomplished with minimal dissection, so that the wind-evoked escape behavior of the animals could be studied following the lesion. Unilateral lesions of GI-2 had no obvious effect on escape behavior, but unilateral removal of GI-1, as well as combined unilateral lesions of GIs 1 and 2, influenced the direction of an animal's initial turning movement in response to a wind puff. These results support the hypothesis that GIs play a role in initiating and guiding the directional, wind-evoked escape response of the cockroach.