title: Maternal deprivation specifically enhances vulnerability to opiate dependence.
abstract: Maternal deprivation has been shown to increase vulnerability to morphine dependence and to disturb the enkephalinergic system in adulthood. To study whether or not this vulnerability to opiates is a specific feature, we examined oral self-administration behaviour of various reinforcing substances. Experiments were performed with morphine (25 mg/l), ethanol (10%), amphetamine (25 mg/l) and cocaine (100 mg/l). Drugs were available in a continuous free choice paradigm during 3 months. Cocaine and ethanol consumption and preference were similar in both deprived and control rats. Deprived rats greatly increased their morphine consumption and 78% of them showed a progressive decrease in morphine aversion. Only a slight, but significant, increase in oral amphetamine consumption was observed in deprived rats when compared with control rats. The difference in amphetamine self-administration in control and deprived rats cannot be explained by a modification of dopamine transporter expression measured by immunoautoradiography. Altogether, we conclude that maternal deprivation worsens inherent susceptibility to dependence, specifically for opiates, and therefore represents a highly valuable model to study environmentally triggered interindividual vulnerability to opiate addiction.
authors.affiliation: Laboratory of Neurobiology and Psychiatry, Inserm U513, Faculty of Medicine, University Paris XII, Créteil, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Vazquez
authors.forename: Bruno
authors.initials: B
authors.lastname: Giros
authors.forename: Valérie
authors.initials: V
authors.lastname: Daugé
mesh_terms: D000661:Amphetamine / Q000008:administration & dosage; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000818:Animals; D001921:Brain / Q000378:metabolism; D002492:Central Nervous System Depressants / Q000008:administration & dosage; D003042:Cocaine / Q000008:administration & dosage; D015259:Dopamine Agents / Q000008:administration & dosage; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage; D000431:Ethanol / Q000008:administration & dosage; D005260:Female; D008297:Male; D008426:Maternal Deprivation; D009020:Morphine / Q000008:administration & dosage*; D011247:Pregnancy; D051381:Rats; D020318:Rats, Long-Evans; D012646:Self Administration; D019966:Substance-Related Disorders / Q000378:metabolism / Q000523:psychology*
chemical_list: D000701:Analgesics, Opioid; D002492:Central Nervous System Depressants; D015259:Dopamine Agents; D050483:Dopamine Plasma Membrane Transport Proteins; D018765:Dopamine Uptake Inhibitors; D000431:Ethanol; D009020:Morphine; D000661:Amphetamine; D003042:Cocaine