Mating-induced differential coding of plant odour and sex pheromone in a male moth

Romina B. Barrozo, David Jarriault, Nina Deisig, Cesar Gemeno, Christelle Monsempes, Philippe Lucas, Christophe Gadenne, Sylvia Anton
European Journal of Neuroscience. 2011-04-14; 33(10): 1841-1850
DOI: 10.1111/j.1460-9568.2011.07678.x

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Innate behaviours in animals can be influenced by several factors, such as the
environment, experience, or physiological status. This behavioural plasticity
originates from changes in the underlying neuronal substrate. A well-described
form of plasticity is induced by mating. In both vertebrates and invertebrates,
males experience a post-ejaculatory refractory period, during which they avoid
new females. 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 response characteristics of the different neuron
types from the periphery to the central level. We examined the response patterns
of pheromone-sensitive and plant volatile-sensitive neurons in virgin and mated
male moths. By using intracellular recordings, we showed that mating changes the
response characteristics of pheromone-sensitive antennal lobe (AL) neurons, and
thus decreases their sensitivity to sex pheromone. Individual olfactory receptor
neuron (ORN) recordings and calcium imaging experiments indicated that 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 to heptanal remained unchanged. We suggest that differential processing
of pheromone and plant odours allows mated males to transiently block their
central pheromone detection system, and increase non-pheromonal odour detection
in order to efficiently locate food sources.

© 2011 The Authors. European Journal of Neuroscience © 2011 Federation of
European Neuroscience Societies and Blackwell Publishing Ltd.


Auteurs Bordeaux Neurocampus