Impairment of thermoregulation, food and water intakes in the rat after hypothalamic injections of 5,6-dihydroxytryptamine

Brain Res. 1975 Sep 5;94(3):491-506. doi: 10.1016/0006-8993(75)90232-2.


A bilateral microinjection into the anterior hypothalamus of 5,6-dihydroxytryptamin (5,6-DHT), a substance that lesions serotonin (5-HT)-containing neurons, caused a rise in the body temperature of the rat. The anatomical sites were the same as those at which 5-HT given in the same dose range (1.25-2.5 mug) evoked a similar hyperthermia. When exposed for one hour to a temperature of either 35 degrees C or 8 degrees C, the rats were not able to defend against the heat or cold, respectively. The magnitude of this thermoregulatory deficit depended upon the dose of 5,6-DHT given as well as the site of injection. A partial recovery from the warmth deficit was evident 13-17 days following the 5,6-DHT microinjection. Food and water intakes were also suppressed significantly and body weights declined concomitantly. These results provide additional evidence to support the view that a serotonergic mechanism in the hypothalamus is involved in both thermoregulation and the control of ingestive behavior.

Publication types

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

MeSH terms

  • 5,6-Dihydroxytryptamine / administration & dosage
  • 5,6-Dihydroxytryptamine / pharmacology*
  • Animals
  • Body Temperature Regulation / drug effects*
  • Body Weight / drug effects
  • Drinking Behavior / drug effects*
  • Feeding Behavior / drug effects*
  • Fever / chemically induced
  • Hypothalamus / drug effects
  • Male
  • Microinjections
  • Rats
  • Serotonin / pharmacology
  • Tryptamines / pharmacology*


  • Tryptamines
  • Serotonin
  • 5,6-Dihydroxytryptamine