Nitric oxide, but not serotonin, is involved in acquisition of food-attraction conditioning in the snail Helix pomatia

Neurosci Lett. 1996 Mar 8;206(1):29-32. doi: 10.1016/0304-3940(96)12434-4.


The effects of inhibition of nitric oxide (NO) or serotonin (injection of nitro-L-arginine methyl ester (L-NAME) or 5,6-dihydroxytryptamine (5,6-DHT), respectively) on food-attraction conditioning was investigated in Helix. Blocking NO synthase (NOS) prior to conditioning significantly impaired the food-finding ability of the snails. Food-conditioned snails, after inhibition of NOS, remained able to locate the conditioned food. These results indicate that the acquisition of memory depends on NO, whereas memory recall and olfactory orientation are not dependent. Ablating the serotonergic system did not influence food-attraction conditioning, suggesting that food-attraction conditioning may be at variance with conventional associative conditioning procedures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5,6-Dihydroxytryptamine / pharmacology
  • Animals
  • Arginine / analogs & derivatives
  • Arginine / pharmacology
  • Conditioning, Operant / drug effects
  • Conditioning, Operant / physiology*
  • Enzyme Inhibitors / pharmacology
  • Feeding Behavior / drug effects
  • Feeding Behavior / physiology*
  • Helix, Snails / physiology*
  • Memory / drug effects
  • NG-Nitroarginine Methyl Ester
  • Nitric Oxide / physiology*
  • Nitric Oxide Synthase / antagonists & inhibitors
  • Serotonin / physiology*
  • Serotonin Agents / pharmacology
  • Smell / physiology


  • Enzyme Inhibitors
  • Serotonin Agents
  • Nitric Oxide
  • Serotonin
  • Arginine
  • Nitric Oxide Synthase
  • NG-Nitroarginine Methyl Ester
  • 5,6-Dihydroxytryptamine