Defense in french
Team : EXPLAIN (Experience-Dependent Plasticity in Insects) – CRCA-CBI
Supervisors : Séverine TRANNOY (CRCA-CBI) et Audrey DUSSUTOUR (CRCA-CBI)
Committee members :
- Mme Maria-Cristina LORENZI, Rapporteure, Université Sorbonne Paris Nord, LEEC
- Serge BIRMAN, Rapporteur, CNRS, ESPCI
- Mme Tihana JOVANIC, Examinatrice, CNRS, NeuroPSI
- Jean-Marc DEVAUD, Examinateur, Université Toulouse III – Paul Sabatier, CBI-CRCA
- Mme Audrey DUSSUTOUR, Directrice de thèse, Université Toulouse III – Paul Sabatier, CBI-CRCA
- Mme Séverine TRANNOY, Co-directrice de thèse, CNRS, CBI-CRCA
Abstract :
Social aggressive and reproductive behaviours are vital for most animals. In one hand, they assure the access to primary resources such as food or mates. On the other hand, they assure offspring and species sustainability. Our aim was to understand how aggressive interactions and their result (victory or defeat) impact males’ reproductive behaviours. Then, we studied the fundamental mechanisms underlying aggressive behaviours dysregulation. For such purposes, we used Drosophila melanogaster as a model. We showed that losers lack of motivation one hour after the defeat in non-competitive context. In competition, losers showed impaired courtship behaviours which are not the consequence of a misperception from the male nor a preference from the females. We then identified two neurons involved in the dysregulation of aggression: the VPM4 and the MBON-11. VPM4 are double-neurotransmissing neurons: they use both glutamate and octopamine as neurotransmitters. We showed that glutamate allowed the regulation of aggression. It inhibits MBON-11 through GluClα receptors. dTrpA1-induced activity in MBON-11 provoked boxing events to occur, and we demonstrated that GABA transmission from MBON-11 is responsible. This thesis is the first step in the comprehension of the emergence of hyper aggressive events in drosophila, and ask the question of the consequence of such dysregulation for individuals’ behaviours.
Campus Université Toulouse III Paul Sabatier
