The effect of social context on decision-making

2012 senior Scholar Award in neuroscience

Evolutionary and ecological theory suggests that the best behavioral strategy can change when competitors are present.  In agreement with this theory, the aggressive, territorial, and foraging behaviors of many animals are regulated by population density.  We hypothesize that population density has an evolutionarily ancient role in shaping animal behaviors, and that the biology of this process could be shared by many animals and perhaps even by humans. 

To explore the roots of density-dependent behaviors, we are characterizing foraging behaviors of the nematode Caenorhabditis elegans. C. elegans does not exhibit obvious aggressive behaviors, but it does have several density-dependent behaviors.  Each animal communicates its developmental stage, sex, and nutritional status to other animals by releasing a cocktail of pheromones.  Other animals respond to this pheromone cocktail with social behaviors, such as aggregation and mating, and also change their foraging strategies based on the density and composition of the pheromone cocktail. 

Our goal is to determine the neuronal, molecular, and developmental mechanisms by which information about population density is transformed into altered behavioral choices.  To this end, we are seeking the genes and neural circuits that integrate density pheromones into foraging decisions, using the powerful experimental tools available in C. elegans.  We hope to learn from this how social context shapes an organism’s broader behavioral repertoire.

Cornelia Bargmann Ph.D.
Rockefeller University