Rat brain serotonin: biochemical and functional evidence for a sex difference

J Neural Transm. 1985;63(3-4):297-313. doi: 10.1007/BF01252033.


Male and female rats were compared with respect to brain serotonin (5-HT) levels, synthetic capacity, receptor sensitivity, and CNS functions. Levels of whole brain 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) were higher in females. The accumulation of 5-HT after treatment with the monoamine oxidase inhibitor pargyline alone and in combination with the 5-HT precursor L-tryptophan was greater in females than in males. 5-HT increased and 5-HIAA decreased to the same extent in both sexes after administration of the 5-HT agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). The temperature fall after all drug treatments was greater in females, but the "5-HT behavioural syndrome" was more pronounced in females merely after pargyline plus tryptophan; the behavioural response after 8-OH-DPAT did not differ between the sexes. These results are indicative of sex differences in the brain 5-HT neuronal systems. They are discussed in relation to differences between males and females in sexual behaviour, aggression and affective disorders.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal / drug effects
  • Behavior, Animal / physiology
  • Body Temperature / drug effects
  • Brain / physiology*
  • Brain Chemistry / drug effects
  • Female
  • Hydroxyindoleacetic Acid / analysis
  • Male
  • Rats
  • Rats, Inbred Strains
  • Serotonin / analysis
  • Serotonin / physiology*
  • Sex Characteristics*


  • Serotonin
  • Hydroxyindoleacetic Acid