Comparative studies of four Drosophila P-insertion mutants with memory defects.

Studies of conditioned reflex courtship suppression in mutant Drosophila males in two tests--a memory retention test (with a virgin female) and a repeat training test (with a fertilized female)--yielded experimental support for a previously suggested physiological model of the acquisition of this reflex. Mutations altered both types of conditioned association suggested in the model, i.e., the association between the conditioned and unconditioned stimuli (lat, rut, dnc, amn, and P153) and the association between the conditioned stimulus and the aversive motivational system mediating the action of the unconditioned stimulus (P171). A third category of mutants appeared to have a disturbance to the function of the aversive motivational system (P95 and P124).