Nicotine pre-treatment reduces sensitivity to the interoceptive stimulus effects of commonly abused drugs as assessed with taste conditioning paradigms

• Published in: Drug and alcohol dependence Vol. 194; pp. 341 - 350
• Main Authors: Loney, G.C., Meyer, P.J.
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.01.2019; Elsevier Science Ltd
• Subjects: Analgesics, Opioid - pharmacology; Animals; Attenuation; Aversive; Caffeine; Caffeine - pharmacology; Central Nervous System Depressants - pharmacology; Central Nervous System Stimulants; Cocaine; Comorbidity; Conditioning; Conditioning, Operant - drug effects; Dosage; Dose-Response Relationship, Drug; Drug abuse; Drug addiction; Drug dosages; Drug screening; Drugs; Ethanol; Ethanol - pharmacology; Exposure; Female; Illicit Drugs - pharmacology; Interoception; Liability; Lithium; Lithium chloride; Lithium Chloride - pharmacology; Male; Morphine; Morphine - pharmacology; Multiple drugs; Narcotics; Nicotine; Nicotine - pharmacology; Nicotine sensitivity; Nicotinic Agonists - pharmacology; Paradigms; Place preference conditioning; Pretreatment; Properties (attributes); Rats; Rats, Long-Evans; Reinforcement, Psychology; Rodents; Sensitivity; Sensitivity analysis; Smoking; Stimulus; Substance use; Substance use disorder; Taste; Taste - drug effects; Morphine; Sensitivity; Cocaine; Interoception; Ethanol; Nicotine
• ISSN: 0376-8716; 1879-0046
• DOI: 10.1016/j.drugalcdep.2018.07.048

•Nicotine pre-treatment attenuated the avoidance induced by commonly abused drugs.•Nicotine had no impact on avoidance induced by lithium chloride.•Female rats appear to be more sensitive to these effects of nicotine.•Nicotine reduced sensitivity to the CTR stimulus properties of these drugs. Drug pre-exposure attenuates sensitivity to the interoceptive stimulus properties of additional subsequently administered drugs in drug-induced conditioned taste avoidance (CTA) and conditioned place preference (CPP) paradigms. Specifically, nicotine, commonly used in conjunction with other addictive substances, attenuates acquisition of ethanol and caffeine CTAs and morphine-induced CPP. Because nicotine use is comorbid with a number of substance use disorders, we systematically examined the effects of nicotine pre-exposure on two different conditioning paradigms involving integration of the interoceptive stimulus properties of multiple commonly abused drugs, in male and female rats, designed to examine both the aversive and reinforcing properties of these drugs. Nicotine dose-dependently interfered with acquisition of CTA to passively administered morphine, ethanol, and cocaine, but not lithium chloride, demonstrating that the effects of nicotine are not simply a matter of reduced orosensory processing or an inability to learn such associations. Moreover, nicotine-treated rats required higher doses of drug in order to develop CTA and did not show increased acceptance of the taste of self-administered ethanol compared with saline-treated rats. These data demonstrate that nicotine pre-exposure attenuates sensitivity to the stimulus effects of multiple drugs in two conditioning paradigms, in a manner which is consistent with a reduced ability to integrate the interoceptive properties of abused drugs. Through reducing these stimulus properties of drugs of abuse, concomitant nicotine use may result in a need to increase either the frequency or strength of doses during drug-taking, thus likely contributing to enhanced addiction liability in smokers.