Early olfactory environment influences social behaviour in adult Octodon degus

PLoS One. 2015 Feb 11;10(2):e0118018. doi: 10.1371/journal.pone.0118018. eCollection 2015.

Abstract

We evaluated the extent to which manipulation of early olfactory environment can influence social behaviours in the South American Hystricognath rodent Octodon degus. The early olfactory environment of newborn degus was manipulated by scenting all litter members with eucalyptol during the first month of life. The social behaviour of sexually mature animals (5-7 months old) towards conspecifics was then assessed using a y-maze to compare the response of control (naïve) and treated animals to two different olfactory configurations (experiment 1): (i) a non-familiarized conspecific impregnated with eucalyptol (eucalyptol arm) presented against (ii) a non-familiarized unscented conspecific (control arm). In addition, in dyadic encounters, we assessed the behaviour of control and eucalyptol treated animals towards a non-familiarized conspecific scented with eucalyptol (experiment 2). We found that control subjects explored and spent significantly less time in the eucalyptol arm, indicating neophobic behaviours towards the artificially scented conspecific. Treated subjects explored and spent similar time in both arms of the maze, showing the same interest for both olfactory stimuli presented. During dyadic encounters in experiment 2, an interaction effect between early experience and sex was observed. Control males escaped and avoided their scented partner more frequently than eucalyptol treated male subjects and than females. Both groups did not differ in the exploration of their scented partners, suggesting that avoidance within agonistic context does not relate to neophobic behaviours. Our results suggest that the exposure to eucalyptol during early ontogeny decreases evasive behaviours within an agonistic context as a result of olfactory learning. Altogether, these results indicate that olfactory cues learned in early ontogeny can influence olfactory-guided behaviours in adult degus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Behavior, Animal*
  • Cues
  • Environment*
  • Female
  • Interpersonal Relations
  • Male
  • Maze Learning
  • Octodon / physiology*
  • Olfactory Perception*
  • Social Behavior*
  • Time Factors

Grant support

NM was founded by Programa de Mejoramiento de la Calidad de la Educación Superior MECESUP UCO-0214, and by Comisión Nacional de Investigación Científica y Tecnológica de Chile CONICYT AT-24050185; RAV was founded by Iniciativa Científica Milenio ICM-P05-002, Comisión Nacional de Investigación Científica y Tecnológica de Chile PFB-23-CONICYT, and Fondo Nacional de Desarrollo Científico y Tecnológico FONDECYT 1140548; JM was founded by Fondo Nacional de Desarrollo Científico y Tecnológico FONDECYT 1120124. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.