The active phase-related increase in corticosterone and aggression are linked

J. Haller, S. Millar, J. V.J. Van De Schraaf, R. E. De Kloet, M. R. Kruk

Research output: Contribution to journalArticle

60 Citations (Scopus)


Recently we demonstrated that corticosterone exerts an acute facilitatory effect on aggression in male rats. Corticosterone production reaches a maximum at the onset of the dark period, while male rats are more aggressive in the dark. Here we present evidence demonstrating that the corticosterone increase at the beginning of the dark period is causally linked to the increase in aggressiveness, We measured plasma corticosterone and quantified aggressive behaviour of male territorial rats at various time points of the day-night transition. Low aggression levels were observed in the full light period when plasma concentrations of corticosterone were low. An increase in plasma corticosterone occurred just prior to the dark phase, when aggressive responding was the highest. Aggressive behaviour remained high in the early dark period when corticosterone was still high. We found that blocking the high affinity mineralocorticoid receptor (MR) with spironolactone (5 or 10 mg/kg) during the early dark period dramatically and specifically reduced territorial aggression.

Original languageEnglish
Pages (from-to)431-436
Number of pages6
JournalJournal of Neuroendocrinology
Issue number5
Publication statusPublished - May 9 2000



  • Aggression
  • Corticosterone
  • Day-night rhythm
  • Mineralocorticoid receptor
  • Rat

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology
  • Endocrine and Autonomic Systems
  • Cellular and Molecular Neuroscience

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