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Long‐lasting increased pain sensitivity in rat following exposure to heroin for the first time
Author(s) -
Laulin JeanPaul,
Larcher Agnès,
Célèrier Evelyne,
Moal Michel Le,
Simonnet Guy
Publication year - 1998
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1046/j.1460-9568.1998.00083.x
Subject(s) - heroin , medicine , sensitivity (control systems) , anesthesia , psychology , psychiatry , drug , electronic engineering , engineering
Acute dependence, defined as a precipitation of somatic signs by an antagonist, may occur after a single administration of an opiate drug. Because hyperalgesia is a consistent sign of the withdrawal syndrome, we tested the effectiveness of heroin, an opiate used by addicts, to induce pain facilitation even after a first exposure to the drug. In opiate‐naive rats, subcutaneous injection of heroin induced analgesia followed by allodynia, a decrease in pain threshold. This latter phenomenon was observed in the absence of noxious stimuli and lasted several days. An N ‐methyl‐ d ‐aspartate (NMDA) receptor antagonist, MK‐801 prevented such long‐lasting allodynia. These results suggest that allodynia is an early sign reflecting neural plasticity associated with the development of dependence.