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/6 J mice to mild and controlled temporary dehydration, i.e., 6 h of water access every 48 h for 15 days. We investigated their social behavior in a social interaction task known to allow free and reciprocal social contact. 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 neurotransmission caused by temporary dehydration stress unbalances choice processes of animals in social context.
Subject(s)
Behavior, Animal/physiology , Dehydration , Raphe Nuclei/cytology , Serotonergic Neurons/cytology , Serotonin/metabolism , Social Behavior , Animals , Cell Count , Dehydration/complications , Dehydration/metabolism , Disease Models, Animal , Dorsal Raphe Nucleus/cytology , Mice , Mice, Inbred C57BL , Social DominanceABSTRACT
The objective of this work was to investigate the implication of serotonin (5-HT) produced in the dorsal and medial raphé nuclei (DRN and MRN) in water homeostasis in desert animal Gerbillus tarabuli. For that, we measured the density of 5-HT immunolabeled neurons in hydrated and dehydrated animals (over 1 and six months). In this work, 5-HT positive neurons showed some change in shape and colour intensity in dehydrated gerbils comparing with hydrated gerbils. Furthermore a differential increase of 5-HT neurons density was observed in DRN subregions and in MRN following 1 and 6 months of dehydration. This study suggested that neurons in DRN and MRN contain 5-HT in various amounts, thus allowing an adapted response to hydration status. These neurons could mediate one of the adaptation mechanisms of this animal to its desert biotope.