Relatório Anual 2010 - Fundação Champalimaud

Susana LimaNeuroethologyGroup membersKensaku Nomoto (Postdoctoral Fellow)Vanessa Urbano (Technician)Léa Zinck (Postdoctoral Fellow)We are interested in the brain mechanisms underlying female mate choice,sexual behaviour and the interaction between the two. As an animalmodel, we use wild-derived inbred house mice, which allow us to performexperiments that address evolutionarily-motivated questions in a controlledlaboratory setting. We are currently investigating how females assess thequality of prospective mates and what aspects of experience shapes femalechoices. We are also actively developing new behavioural paradigms tomeasure and manipulate the variables that affect female sexual arousal andreceptivity. To address our goal of understanding how patterns of neuralactivity give rise to these processes, we employ approaches ranging fromelectrophysiological recordings in behaving animals to genetic manipulationof neuronal networks.Neuronal mechanisms for mate choice in miceThe hybrid zone between Musmusculus musculus and Musmusculus domesticus in Europe.House mice in Europe are derivedfrom a common ancester originatingin the Indian subcontinent, whichspread through Europe withagriculture. Two subspecies havedeveloped in allopatry: Mus musculusmusculus and Mus musculusdomesticus. Starting 6800 years ago,these two subspecies establisheda contact zone, spanning fromDenmark to the Mediterranean.Thishybrid zone exhibits assymetric matechoice, which in part has contributedto the still current separation ofthe two subspecies: while musculusfemales prefer to mate withmusculus males, domesticus femalesmate indiscriminately. We havedeveloped a behavioural paradigmin the laboratory using inbred wildderived animals of the subspeciesmusculus (PWD and PWK) andlaboratory strains of mice (Black 6)as domesticus.Our main goal was to develop a behavioural paradigm of mate choice in miceto then investigate the neuronal mechanisms responsible for representingmates of different values and how comparison of competing alternativesare made. We have used a mate choice paradigm inspired by the naturalsituation observed in the hybrid zone between Mus musculus musculus andMus musculus domesticus in Europe.In 2010 we have established a mate choice paradigm with M. m. musculusand M. m. domesticus, where musculus females exhibit a strong and reliablepreference for their own subspecies. We have also established that thispreference is influenced by early imprinting mechanisms and it increaseswith multiple testing. Furthermore, the preference for a specific male isnot absolute, but rather flexible and dependent on the alternatives thatare available.Neuronal mechanisms underlying sex hormone-dependent switching ofsexual receptivityFemale sexual receptivity changes across the reproductive cycle, beingmaximal during the fertile phase. This represents an interestingFC Relatório Anual 2010 24