Effect of water restriction stress on social behavior in mice: Impact on serotonergic system plasticity

Abstract : We explored here the hypothesis that temporary chronic water restriction in mice affects social behavior, via its action on the density of 5-HT neurons in dorsal and median raphe nuclei (DRN and MRN). For that, we submitted adult C57BL/6J mice to mild and controlled temporary dehydration, i.e., 6h of water access every 48h for 15 days. We investigated their social behavior in a social interaction task known to allow free and reciprocal social contact and to rely on prefrontal cortex activity and monoaminergic prefrontal input. Results showed that temporary dehydration increases significantly time spent in social contact and social dominance. It also expands 5-HT neuron density within both DRN and MRN and the behavioral and neuronal plasticity were positively correlated. Our findings suggest that disturbance in 5-HT innervation caused by temporary dehydratation stress unbalances choice processes of animals in social context.