Sweet success, bitter defeat: a taste phenotype predicts social status in selectively bred rats

PLoS One. 2012;7(10):e46606. doi: 10.1371/journal.pone.0046606. Epub 2012 Oct 3.

Abstract

For social omnivores such as rats and humans, taste is far more than a chemical sense activated by food. By virtue of evolutionary and epigenetic elaboration, taste is associated with negative affect, stress vulnerability, responses to psychoactive substances, pain, and social judgment. A crucial gap in this literature, which spans behavior genetics, affective and social neuroscience, and embodied cognition, concerns links between taste and social behavior in rats. Here we show that rats selectively bred for low saccharin intake are subordinate to high-saccharin-consuming rats when they compete in weight-matched dyads for food, a task used to model depression. Statistical and experimental controls suggest that differential resource utilization within dyads is not an artifact of individual-level processes such as apparatus habituation or ingestive motivation. Tail skin temperature measurements showed that LoS rats display larger hyperthermic responses to social interaction after status is established, evidence linking taste, social stress, autonomic reactivity, and depression-like symptoms. Based on regression using early- and late-competition predictors to predict dyadic disparity in final competition scores, we tentatively suggest that HiS rats emerge as dominant both because of an "early surge" on their part and because LoS acquiesce later. These findings should invigorate the comparative study of individual differences in social status and its relationship to mental and physical health.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal / drug effects
  • Competitive Behavior / drug effects*
  • Feeding Behavior / drug effects
  • Fever / metabolism
  • Male
  • Phenotype
  • Rats
  • Saccharin / pharmacology*
  • Skin / metabolism
  • Sweetening Agents / pharmacology*
  • Taste / physiology

Substances

  • Sweetening Agents
  • Saccharin

Grants and funding

All funding was intramural. It included a fellowship for the first author made possible due to a grant to Occidental College from the Fletcher-Jones Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.