castanyes blaves

Abstract

Social or behavioural disorders affect a quarter of individuals at some time during their lives however the molecules and mechanisms that mediate social cues, process their meaning, and initiate the corresponding behaviour are unknown. Instinctive social behaviours in mammals are thought to be largely promoted by pheromones: specialized olfactory cues secreted by one animal that directly influence the behaviour of another.  Here I will describe studies into two instinctive, olfactory mediated behaviours in mice, aggression and pup suckling. 

Our studies found that aggression is promoted by specific protein pheromones excreted in male urine. These activate specialized, finely tuned sensory neurons in the noses of other males, resulting in a robust aggressive behaviour in the recipient. Our genomic and functional characterization of the gene family encoding these pheromones reveals an extraordinary scope for information-coding. I will describe our recent efforts to elucidate their social significance using cellular and behavioural techniques.

Pup suckling is a behaviour that is found in all mammals and is thought to be promoted by pheromones emitted by the mother and detected by the infant. We found that newborn mice do use maternal odour cues to promote suckling but, in contrast to the aggression pheromones, these cues are not genetically predetermined to elicit behaviour. Instead, the cues are complex, variable and learned by pups around birth. Suckling is subsequently initiated when the pup recognizes the same odour pattern in the context of their mother's nipple. The sensory neurons that mediate this are not specialized and found in the noses of all mammals, including humans.

Together these studies demonstrate a diversity of mechanisms and molecules that underlie instinctive behaviours, and are a first step towards understanding the neural circuitry of social interaction.