Mating-induced differencial coding of plant odour and sex pheronome in a male moth

BARROZO RB, JARRIAULT D, DEISIG N, GEMENO C, MONSEMPES C, LUCAS P, GADENNE C, ANTON S

EUROPEAN JOURNAL OF NEUROSCIENCE

WILEY-BLACKWELL PUBLISHING, INC

Año: 2011 vol. 33 p. 1841 - 1850

0953-816X

Innate behaviours in animals can be influenced by several factors, such as the environment, experience, or physiological status. Thisbehavioural plasticity originates from changes in the underlying neuronal substrate. A well-described form of plasticity is induced bymating. In both vertebrates and invertebrates, males experience a post-ejaculatory refractory period, during which they avoid newfemales. In the male moth Agrotis ipsilon, mating induces a transient inhibition of responses to the female-produced sex pheromone.To understand the neural bases of this inhibition and its possible odour specificity, we carried out a detailed analysis of the responsecharacteristics of the different neuron types from the periphery to the central level. We examined the response patterns ofpheromone-sensitive and plant volatile-sensitive neurons in virgin and mated male moths. By using intracellular recordings, weshowed that mating changes the response characteristics of pheromone-sensitive antennal lobe (AL) neurons, and thus decreasestheir sensitivity to sex pheromone. Individual olfactory receptor neuron (ORN) recordings and calcium imaging experiments indicatedthat pheromone sensory input remains constant. On the other hand, calcium responses to non-pheromonal odours (plant volatiles)increased after mating, as reflected by increased firing frequencies of plant-sensitive AL neurons, although ORN responses toheptanal remained unchanged. We suggest that differential processing of pheromone and plant odours allows mated males totransiently block their central pheromone detection system, and increase non-pheromonal odour detection in order to efficientlylocate food sources.