Description du projet
Le rôle du cervelet dans la construction des nids chez les oiseaux
La construction d’un nid n’est pas instinctive chez les oiseaux, mais s’apprend au cours du processus de construction. Chez toutes les espèces d’oiseaux, plus le nid est complexe, plus le degré de plis de la région du cervelet augmente dans le cerveau de la créature. Le projet NEURONESt, financé par l’UE, permettra de vérifier si cette activation du cervelet est liée à des aspects cognitifs de la construction d’un nid, comme la planification ou la résolution de problèmes, et/ou à une composante purement manipulatoire. La construction d’un nid constitue également un comportement clé pour la reproduction et la santé des oiseaux. Des expériences seront donc menées pour déterminer l’implication des stéroïdes sexuels, de leurs récepteurs et de leurs effecteurs traditionnels dans la construction d’un nid, en faisant appel à une combinaison de biologie moléculaire, d’études des gènes immédiats précoces et de manipulation expérimentale des niveaux d’hormones sexuelles.
Objectif
Bird nests may be the most familiar of the animal-made objects, but still we don't know much about how birds actually make them. Using zebra finches as a model system, Healy and Meddle have overturned the folk wisdom that bird nests are the results of an instinctive behaviour, showing that birds learn about the physical nature of the world when building. Using the immediate early gene (IEG) c-Fos, a marker of neuronal activity, they have also begun to identify the key neuronal structures active during nest building (NB), including among others the cerebellum (CB). Interestingly, across bird species, as the complexity of the nest increases so does the degree of folding of the CB, a brain region traditionally associated with motor control, but more recently with cognition. In the first part of the project, I will thus test whether this reported pattern of cerebellar activation relates to cognitive aspects of NB (such as planning or problem solving) and/or to a purely manipulative component. In addition of being a building activity, NB is also a key behaviour for birds' reproduction and fitness. Interestingly, most of the brain areas involved during NB are sex-steroid sensitive. I will thus determine in a second experiment whether and how sex hormones play a role in NB, as they do for so many other behaviours. To do this I will test the involvement of sex steroids, their receptors and traditional effectors in NB, using a combination of molecular biology, IEG studies and experimental manipulation of sex hormone levels. This work will lead to the first major synthesis of the cognitive, neurobiological and molecular mechanisms underlying NB by birds. It will also provide significant insights into the neural bases of other building behaviours, such as tool manufacture, and will open new avenues of research about the role(s) environmental pollutants acting as endocrine disruptors play on brain functioning, and how they interfere with birds’ reproduction and fitness.
Champ scientifique
Mots‑clés
Programme(s)
Régime de financement
MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF)Coordinateur
KY16 9AJ St Andrews
Royaume-Uni