Isatin, a putative anxiogenic endocoid, induces memory dysfunction in rats

Indian J Exp Biol. 1995 Aug;33(8):576-9.


Isatin (2,3-dioxoindole), one of the components of tribulin, which has been postulated to function as an endogenous marker of stress and anxiety, was shown to induce a dose-related attenuation of learning acquisition in an active avoidance test and inhibition of learning retention, or memory, in a step-down passive avoidance paradigm and transfer latency in an elevated plus-maze, in rats. Earlier studies have indicated that isatin functions as a 5-hydroxytryptamine (5-HT)3 receptor agonist in its anxiogenic activity in rats and is an antagonist at mammalian atrial natriuretic peptide (ANP) receptors. Since 5-HT3 receptor antagonists and centrally administered ANP have been shown to facilitate learning and memory, the observed memory dysfunction induced by isatin can be attributed to its receptor activity at 5-HT3 and ANP receptors. The investigation also indicates that anxiogenic agents are likely to disrupt memory functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anxiety Disorders / chemically induced*
  • Female
  • Isatin / toxicity*
  • Male
  • Memory Disorders / chemically induced*
  • Rats
  • Receptors, Atrial Natriuretic Factor / antagonists & inhibitors*
  • Serotonin Receptor Agonists / toxicity*


  • Serotonin Receptor Agonists
  • Isatin
  • Receptors, Atrial Natriuretic Factor