Novelty-induced locomotion is positively associated with cocaine ingestion in adolescent rats; anxiety is correlated in adults

• Published in: Pharmacology, biochemistry and behavior Vol. 91; no. 3; pp. 398 - 408
• Main Authors: Walker, Q. David, Schramm-Sapyta, Nicole L., Caster, Joseph M., Waller, Samuel T., Brooks, Matthew P., Kuhn, Cynthia M.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Inc 01.01.2009; Elsevier
• Subjects: Addiction; Aging - psychology; Animals; Anxiety; Anxiety - psychology; Biological and medical sciences; Cocaine - chemistry; Cocaine - pharmacology; Cocaine-Related Disorders - psychology; Data Interpretation, Statistical; Development; Environment; Female; Male; Medical sciences; Motor Activity - drug effects; Neuropharmacology; Novelty-seeking; Oral cocaine; Pharmaceutical Solutions; Pharmacology. Drug treatments; Psychoanaleptics: cns stimulant, antidepressant agent, nootropic agent, mood stabilizer; Psychoanaleptics: cns stimulant, antidepressant agent, nootropic agent, mood stabilizer..., (alzheimer disease); Psychology. Psychoanalysis. Psychiatry; Psychopharmacology; Rats; Reward; Sex Characteristics; Sex differences; Development; Oral cocaine; Sex differences; Novelty-seeking; Anxiety; Addiction; Human; Novelty seeking; CNS stimulant; Rat; Psychotropic; Rodentia; Sex; Oral administration; Young animal; Ester; Locomotion; Vertebrata; Mammalia; Adult; Cocaine; Drug of abuse
• ISSN: 0091-3057; 1873-5177
• DOI: 10.1016/j.pbb.2008.08.019

The present studies assessed the roles of sex, age, novelty-seeking and plus-maze behavior on cocaine drinking in rats. Cocaine/saccharin solution was available in three daily, 5-hour sessions then a saccharin-only solution was also available in following sessions. In the one-bottle drinking phase, early and late adolescent males, post-natal day 28 (PN28) and PN42, consumed more cocaine/saccharin solution than young adults (PN65), but females did not exhibit significant age differences. Adolescents of both sexes consumed more cocaine/saccharin than adults during choice drinking. Saccharin availability in the two-bottle trials decreased cocaine/saccharin consumption in PN28 and PN65 rats. After a drug-free period, cocaine-stimulated locomotion was lower in cocaine/saccharin drinking than saccharin-only males, indicating tolerance. We tested the hypothesis that individual differences in pre-screened behavioral traits would correlate with cocaine/saccharin consumption in PN28 and PN65 male rats. High locomotor responses to novelty were associated with greater cocaine/saccharin drinking in adults in one-bottle sessions. In the subsequent choice drinking phase, correlations were age-specific. Adolescents with high novelty-induced locomotion and adults that spent less time on open arms of the elevated plus-maze drank more cocaine/saccharin. Thus, behavioral phenotypes correlated with individual differences in cocaine/saccharin consumption in an age-related manner.