Selective serotonin reuptake inhibitor (fluoxetine) decreases the effects of ghrelin on memory retention and food intake

Regul Pept. 2007 Apr 5;140(1-2):65-73. doi: 10.1016/j.regpep.2006.11.012. Epub 2006 Dec 26.

Abstract

Ghrelin (Ghr) is an appetite stimulating hormone that is produced peripherally, by the stomach, and centrally as well. Previous investigations show that Ghr increases food intake and memory retention in rats, and that extra-hypothalamic structures, such as the hippocampus, participate in these effects. In the present work we analyzed the effect on food intake and memory retention induced by Ghr after serotonin (5-HT) availability modification at the serotoninergic synapses. Animals only treated with a selective serotonin reuptake inhibitor (SSRI), fluoxetine (FLU) 5 mg/kg or clomipramine (CLO) 2.5 and 5 mg/kg, showed a significant reduction in both food intake and memory retention. On the contrary, Ghr administration induces a significant increase in food intake and a dose-dependent increase in short and long term memory retention. When the animals were treated with FLU prior to Ghr injection, the food intake induced, as well as the expression of short and long term memory retention, was decreased. In conclusion, evidence presented in this paper suggests that the effects of Ghr on both feeding and memory retention in extra-hypothalamic structures such as the hippocampus, could depend on the availability of 5-HT.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / drug effects
  • Clomipramine / pharmacology
  • Dose-Response Relationship, Drug
  • Eating / drug effects*
  • Fluoxetine / pharmacology*
  • Ghrelin
  • Hippocampus / drug effects
  • Male
  • Memory / drug effects*
  • Models, Biological
  • Peptide Hormones / pharmacology*
  • Rats
  • Rats, Wistar
  • Selective Serotonin Reuptake Inhibitors / pharmacology*

Substances

  • Ghrelin
  • Peptide Hormones
  • Serotonin Uptake Inhibitors
  • Fluoxetine
  • Clomipramine