The effects of environmental enrichment on nicotine condition place preference in male rats.

Abstract

Environmental enrichment has previously been shown to alter sensitivity to psychostimulants and opiates in various preclinical models. However, little research has been conducted studying the effects of environmental enrichment on the more commonly abused drug, nicotine. The current study raised male rats in either enriched conditions (EC) or isolated conditions (IC) and tested the animals' sensitivity to acquisition, extinction and reinstatement of nicotine conditioned place preference (CPP). Using a 3-chamber CPP apparatus, male Sprague-Dawley rats were conditioned with 1 of 3 doses of nicotine (0.4, 0.6, and 0.8 mg/kg) or saline on alternating days across 8 conditioning trials, followed by a test day for a nicotine-induced CPP response. Next, the animals had 5 extinction sessions followed by a nicotine-primed reinstatement session. EC rats displayed nicotine CPP at all 3 doses, whereas IC rats failed to show significant nicotine CPP relative to saline controls. EC rats also showed extinction of the nicotine-induced CPP response by the fifth extinction session for all 3 nicotine doses tested. However, only the 2 highest doses of the nicotine prime reinstated a CPP response in EC rats relative to saline controls. Taken together, these findings suggest that environmental enrichment may increase sensitivity to the rewarding effects of nicotine.

Therapeutic efficacy of environmental enrichment for substance use disorders

“…Similar findings were observed by others when the conditioning drugs were psychostimulants (Schenk et al 1986;Thiriet et al 2008;Hofford et al 2014;Galaj et al 2017) or opiates (Smith et al 2005). Also, other studies found that EE (including access to a running wheel), when introduced before conditioning, actually strengthened nicotine (Ewin et al 2015), morphine (Eisenstein and Holmes 2007) or cocaine CPP (Smith et al 2008) and delayed the extinction of CPP (Mustroph et al 2011). A very recent study found no evidence of wheel running during rearing on the development of cocaine CPP in mice (Lespine and Tirelli 2019).…”

Post-weaning Environmental Enrichment, But Not Chronic Maternal Isolation, Enhanced Ethanol Intake during Periadolescence and Early Adulthood

“…A facilitating effect of EE upon drug reactivity has also been observed with other drugs. EE exposure resulted in heightened amphetamine ( Bowling and Bardo, 1994 ) or nicotine ( Ewin et al, 2015 ) induced conditioned place preference.…”

Environmental enrichment decreases chronic psychosocial stress-impaired extinction and reinstatement of ethanol conditioned place preference in C57BL/6 male mice

“…Also, EE attenuated cocaine-seeking behavior compared with isolated conditions in rats (Thiel et al 2012). Similarly, the effects of EE on nicotine-induced CPP in male rats were assessed and the results indicated that, in enriched conditions, rats showed extinction of the nicotine-induced CPP response by the 5th extinction session (Ewin et al 2015). Also, while animals in standard and enriched housing conditions intravenously selfadministered similar amounts of heroin over 14 days, EE diminished extinction response in male Sprague-Dawley rats (Imperio et al 2018).…”