Comparison of nicotine oral consumption and baseline anxiety measures in adolescent and adult C57BL/6J and C3H/Ibg mice

Abstract

Approximately 80% of smokers initiate tobacco use during adolescence, suggesting that nicotine initiation and nicotine dependence have a substantial age component. There also is a substantial genetic influence on smoking behaviors such as age of initiation and the development of nicotine dependence. The goal of this study was to examine both genetic background and age dependent effects on oral nicotine self-administration and anxiety-like behaviors in mice. Two inbred mouse strains (C3H/Ibg and C57BL/6J) were assessed for oral nicotine preference during early adolescence (postnatal day 24–35), middle adolescence (postnatal day 36–47), late adolescence (postnatal day 48–59), adulthood (postnatal day 60+) and 2 months following their initial exposure to nicotine. Mice also were assessed for innate anxiety using an elevated zero maze to determine if age and/or genetic background influenced anxiety-like behaviors. Results indicated that initial nicotine preference and nicotine preference two months after an initial exposure are both strain and age dependent. Age also had an effect on some baseline anxiety measures but strain differences for most zero maze measures were present throughout all age groups. In general, early adolescent C3H mice exhibited greater nicotine preference while C57 mice displayed greater preference during middle adolescence and upon a second exposure to nicotine. In contrast, C57 mice exhibited reduced anxiety across all ages tested. These studies indicate that genetic background should be considered when evaluating age-dependent effects of drugs of abuse and baseline anxiety-like behaviors.

Prepubertal Fischer 344 rats display stronger morphine‐induced taste avoidance than prepubertal Lewis rats

“…As described, prepubescent F344 rats acquired the avoidance at a faster rate and to a stronger degree than animals in the LEW strain, a pattern that paralleled the results of Experiment 1 with adults under the modified deprivation procedure and those previously reported with adults in these strains (Davis et al, 2012;Gomez-Serrano et al, 2009;Lancellotti et al, 2001). The present results demonstrate that differences in morphine-induced taste avoidance are evident as early as prepubescence and are developmentally stable, suggesting that these differences are highly heritable (for other developmental strain assessments, see Allam, 2012;Fairless et al, 2012;Farid et al, 2000;Moore et al, 2011Moore et al, , 2013Paylor et al, 1996;Satinder, 1981;Sinaiko & Mirkin, 1974;Tonkiss et al, 1992;Vogl et al, 1994;Wilking et al, 2012).…”

Pharmacokinetic and Pharmacodynamics Studies of Nicotine After Oral Administration in Mice: Effects of Methoxsalen, a CYP2A5/6 Inhibitor

“…For example, in mice with very rapid rates of nicotine metabolism, small differences in levels or function of CYP2A5 between different mouse strains may result in substantially differing nicotine pharmacological effects. Thus, pharmacokinetic differences likely contribute to differences in effects seen between studies employing the use of different mouse strains (Locklear, McDonald, Smith, & Fryxell, 2012;Wilking et al, 2012).…”

The nicotine + alcohol interoceptive drug state: contribution of the components and effects of varenicline in rats

“…When nicotine was administered alone, it was dissolved in distilled water. All nicotine doses are expressed in base form and the pH of solutions was not adjusted as is common in studies using oral routes of nicotine administration (Alsharari et al 2014; Aschhoff et al 2000; Wilking et al 2012). The N+A solution was administered IG, with volumes varied by weight to obtain the desired doses.…”