Alcohol-heightened aggression in mice: attenuation by 5-HT1A receptor agonists

Psychopharmacology (Berl). 1998 Sep;139(1-2):160-8. doi: 10.1007/s002130050701.


One of the critical mechanisms by which alcohol heightens aggression involves forebrain serotonin (5-HT) systems, possibly via actions on 5-HT1A receptors. The present experiments tested the hypothesis that activating 5-HT1A receptors by selective agonists will block the aggression-heightening effects of ethanol. Initially, the selective antagonist WAY 100635 was used to assess whether or not the changes in aggressive behavior after treatment with 8-OH-DPAT and flesinoxan result from action at the 5-HT1A receptors. Resident male CFW mice engaged in aggressive behavior (i.e. attack bites, sideways threats, tail rattle) during 5-min confrontations with a group-housed intruder male. Quantitative analysis of the behavioral repertoire revealed systematic reductions in all salient elements of aggressive behavior after treatment with 8-OH-DPAT (0.1-0.3 mg/kg, i.p.) or flesinoxan (0.1-1.0 mg/kg, i.p.). The 5-HT1A agonists also reduced motor activities such as walking, rearing and grooming, although to a lesser degree. Pretreatment with the antagonist WAY 100635 (0.1 mg/kg, i.p.) shifted the agonist dose-effect curves for behavioral effects to the right. In a further experiment, oral ethanol (1.0 g/kg, p.o.) increased the frequency of attacks in excess of 2 SD from their mean vehicle level of attacks in 19 out of 76 resident mice. Low doses of 8-OH-DPAT (0.03-0.3 mg/kg) and flesinoxan (0.1, 0.3, 0.6 mg/kg), given before the ethanol treatment, attenuated the alcohol-heightened aggression in a dose-dependent fashion. By contrast, these low 5-HT1A agonist doses affected motor activity in ethanol-treated resident mice to a lesser degree, suggesting behavioral specificity of these anti-aggressive effects. The current results support the hypothesized significant role of 5-HT1A receptors in the aggression-heightening effects of alcohol. If these effects are in fact due to action at somatodendritic 5-HT1A autoreceptors, then the anti-aggressive effects would be associated with decreased 5-HT neurotransmission.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 8-Hydroxy-2-(di-n-propylamino)tetralin / pharmacology
  • Aggression / drug effects*
  • Animals
  • Dose-Response Relationship, Drug
  • Ethanol / antagonists & inhibitors
  • Ethanol / pharmacology*
  • Male
  • Mice
  • Piperazines / pharmacology
  • Receptors, Serotonin / drug effects*
  • Receptors, Serotonin, 5-HT1
  • Serotonin Receptor Agonists / pharmacology*


  • Piperazines
  • Receptors, Serotonin
  • Receptors, Serotonin, 5-HT1
  • Serotonin Receptor Agonists
  • Ethanol
  • flesinoxan
  • 8-Hydroxy-2-(di-n-propylamino)tetralin