title: Unique Behavioral and Neurochemical Effects Induced by Repeated Adolescent Consumption of Caffeine-Mixed Alcohol in C57BL/6 Mice.
abstract: The number of highly caffeinated products has increased dramatically in the past few years. Among these products, highly caffeinated energy drinks are the most heavily advertised and purchased, which has resulted in increased incidences of co-consumption of energy drinks with alcohol. Despite the growing number of adolescents and young adults reporting caffeine-mixed alcohol use, knowledge of the potential consequences associated with co-consumption has been limited to survey-based results and in-laboratory human behavioral testing. Here, we investigate the effect of repeated adolescent (post-natal days P35-61) exposure to caffeine-mixed alcohol in C57BL/6 mice on common drug-related behaviors such as locomotor sensitivity, drug reward and cross-sensitivity, and natural reward. To determine changes in neurological activity resulting from adolescent exposure, we monitored changes in expression of the transcription factor ΔFosB in the dopaminergic reward pathway as a sign of long-term increases in neuronal activity. Repeated adolescent exposure to caffeine-mixed alcohol exposure induced significant locomotor sensitization, desensitized cocaine conditioned place preference, decreased cocaine locomotor cross-sensitivity, and increased natural reward consumption. We also observed increased accumulation of ΔFosB in the nucleus accumbens following repeated adolescent caffeine-mixed alcohol exposure compared to alcohol or caffeine alone. Using our exposure model, we found that repeated exposure to caffeine-mixed alcohol during adolescence causes unique behavioral and neurochemical effects not observed in mice exposed to caffeine or alcohol alone. Based on similar findings for different substances of abuse, it is possible that repeated exposure to caffeine-mixed alcohol during adolescence could potentially alter or escalate future substance abuse as means to compensate for these behavioral and neurochemical alterations.
authors.affiliation: Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, 47907, United States of America.
authors.forename: Meridith T
authors.initials: MT
authors.lastname: Robins
authors.affiliation: Department of Neuroscience, University of California San Francisco, San Francisco, California, 94158, Unites States of America.
authors.forename: Julie
authors.initials: J
authors.lastname: Lu
authors.affiliation: Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, 47907, United States of America.
authors.forename: Richard M
authors.identifier: http://orcid.org/0000-0002-9957-1633
authors.initials: RM
authors.lastname: van Rijn
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D000818:Animals; D002110:Caffeine / Q000008:administration & dosage / Q000494:pharmacology*; D002492:Central Nervous System Depressants / Q000008:administration & dosage / Q000494:pharmacology; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology; D003213:Conditioning, Psychological / Q000187:drug effects; D004298:Dopamine / Q000378:metabolism; D061215:Energy Drinks; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D012201:Reward; D055815:Young Adult
chemical_list: D002492:Central Nervous System Depressants; D000697:Central Nervous System Stimulants; C483819:Fosb protein, mouse; D016760:Proto-Oncogene Proteins c-fos; D002110:Caffeine; D000431:Ethanol; D004298:Dopamine