Nitric oxide is required for tactile learning in Octopus vulgaris

Proc Biol Sci. 1994 Jun 22;256(1347):269-73. doi: 10.1098/rspb.1994.0080.


Nitric oxide, produced by nitric oxide synthase in brain tissue, is essential for several different kinds of learning in vertebrates. We present the first evidence that it is also essential for learning in an invertebrate. Intramuscular injections of an inhibitor of the enzyme completely block touch learning in Octopus vulgaris. Eight control animals learned a touch paradigm, but none of eight synthase-inhibited ones learned it.

Publication types

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

MeSH terms

  • Amino Acid Oxidoreductases / metabolism
  • Animals
  • Arginine / analogs & derivatives*
  • Arginine / pharmacology
  • Brain / physiology
  • Conditioning, Psychological
  • Learning / drug effects
  • Learning / physiology*
  • Male
  • NG-Nitroarginine Methyl Ester
  • Nitric Oxide / physiology*
  • Nitric Oxide Synthase
  • Octopodiformes / physiology*
  • Touch
  • Vertebrates


  • Nitric Oxide
  • Arginine
  • Nitric Oxide Synthase
  • Amino Acid Oxidoreductases
  • NG-Nitroarginine Methyl Ester