Brief predator sound exposure elicits behavioral and neuronal long-term sensitization in the olfactory system of an insect

ANTON S., EVENGAARD K,, BARROZO R.B., ANDERSON P., SKALS N

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

NATL ACAD SCIENCES

Año: 2011 vol. 108 p. 3401 - 3405

0027-8424

Modulation of sensitivity to sensory cues by experience is essentialfor animals to adapt to a changing environment. Sensitization andadaptation to signals of the same modality as a function of experiencehave been shown in many cases, and some of the neurobiologicalmechanisms underlying these processes have beendescribed. However, the influence of sensory signals on the sensitivityof a different modality is largely unknown. In males of thenoctuid moth, Spodoptera littoralis, the sensitivity to the femaleproducedsex pheromone increases 24 h after a brief preexposurewith pheromone at the behavioral and central nervous level. Herewe show that this effect is not confined to the same sensory modality:the sensitivity of olfactory neurons can also be modulated byexposure to a different sensory stimulus, i.e., a pulsed stimulus mimickingecholocating sounds from attacking insectivorous bats. Wetested responses of preexposed male moths in a walking bioassayand recorded from neurons in the primary olfactory center, the antennallobe. We show that brief exposure to a bat call, but not toa behaviorally irrelevant tone, increases the behavioral sensitivityof male moths to sex pheromone 24 h later in the same way asexposure to the sex pheromone itself. The observed behavioralmodification is accompanied by an increase in the sensitivity of olfactoryneurons in the antennal lobe. Our data provide thus evidencefor cross-modal experience-dependent plasticity not onlyon the behavioral level, but also on the central nervous level, inan insect.