Role of 5-HT Receptor Subtypes in the Modulation of Dorsal Periaqueductal Gray Generated Aversion

Pharmacol Biochem Behav. 1995 Sep;52(1):1-6. doi: 10.1016/0091-3057(94)00402-5.


To explore the role of 5-HT receptor subtypes in controlling aversion, we measured the effect of 5-HT1A and 5-HT2A/2C receptor agonists microinjected into the dorsal periaqueductal gray (DPAG) of rats on aversive behavior induced by electrical stimulation of the same brain area. The 5-HT1A agonists 8-OH-DPAT (4-16 nmol) and BAY-R-1531 (4-16 nmol) raised the threshold of aversive electrical stimulation in a dose-dependent way. Similarly, microinjection of the 5-HT2A/2C agonist DOI (4-16 nmol) increased the aversive mCPP (16 and 32 nmol) was ineffective. Previous intra-DPAG administration of the 5-HT1A receptor blocker NAN-190 (40 nmol) antagonized the antiaversive effect of 8-OH-DPAT (8 nmol), whereas pretreatment with the 5-HT2A receptor blocker spiperone (10 nmol) antagonized the effect of DOI (16 nmol). Spiperone also counteracted the effect of 8-OH-DPAT and NAN-190 counteracted the effect of DOI. These results indicate that activation of 5-HT1A and 5-HT2A receptors inhibits aversion in the DPAG and that both receptors have to be functional for the expression of each one's activation to occur.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 8-Hydroxy-2-(di-n-propylamino)tetralin / administration & dosage
  • 8-Hydroxy-2-(di-n-propylamino)tetralin / antagonists & inhibitors
  • 8-Hydroxy-2-(di-n-propylamino)tetralin / pharmacology
  • Amphetamines / administration & dosage
  • Amphetamines / antagonists & inhibitors
  • Amphetamines / pharmacology
  • Animals
  • Avoidance Learning / drug effects*
  • Dose-Response Relationship, Drug
  • Electric Stimulation
  • Injections
  • Male
  • Periaqueductal Gray / physiology*
  • Rats
  • Rats, Wistar
  • Receptors, Serotonin / drug effects
  • Receptors, Serotonin / metabolism*
  • Serotonin Antagonists / administration & dosage
  • Serotonin Antagonists / pharmacology
  • Serotonin Receptor Agonists / administration & dosage
  • Serotonin Receptor Agonists / pharmacology


  • Amphetamines
  • Receptors, Serotonin
  • Serotonin Antagonists
  • Serotonin Receptor Agonists
  • 8-Hydroxy-2-(di-n-propylamino)tetralin
  • 4-iodo-2,5-dimethoxyphenylisopropylamine