Activation of serotonergic neurotransmission during the performance of aggressive behavior in rats

Behav Neurosci. 2003 Aug;117(4):667-74. doi: 10.1037/0735-7044.117.4.667.


High aggression is often linked to lowered serotonin (5-HT) neurotransmission. Although this may hold for high aggression as a trait characteristic of an individual, serotonergic activity is probably increased during performance of aggressive behavior. To test this hypothesis, first, the 5-HT1A agonist alnespirone and gamma aminobutyric acid-A agonist muscimol were administered into the dorsal raphe nucleus. These treatments, which inhibit 5-HT neuronal activity, were shown to decrease performance of aggressive behavior. Second, after a resident-intruder test, the activation of 5-HT neurons (measured by c-fos expression) was increased in high-aggressive rats, compared with low-aggressive rats or control rats that were not subjected to a social confrontation. Results show that performance of aggressive behavior increases 5-HT neuronal activity and that preventing this activation inhibits expression of aggressive behavior.

MeSH terms

  • Aggression / physiology*
  • Animals
  • GABA Agonists / pharmacology
  • Male
  • Muscimol / pharmacology
  • Neurons / physiology
  • Rats
  • Serotonin / metabolism
  • Serotonin / pharmacology*
  • Serotonin Receptor Agonists / pharmacology
  • Spiro Compounds / pharmacology
  • Synaptic Transmission / physiology*


  • GABA Agonists
  • Serotonin Receptor Agonists
  • Spiro Compounds
  • Muscimol
  • Serotonin
  • alnespirone