Capacity of novelty-induced locomotor activity and the hole-board test to predict sensitivity to the conditioned rewarding effects of cocaine

Differential Brain, Cognitive and Motor Profiles Associated with Partial Trisomy. Modeling Down Syndrome in Mice

“…For discriminative memory we used the altered context version of the fear-conditioning test (Contarino et al 2002 ). We add the exploratory behavior that plays a crucial role in learning (Arenas et al 2014 ;Sanderson and Bannerman 2011 ). It was assessed using an automatic hole-board.…”

Acute social defeat stress increases the conditioned rewarding effects of cocaine in adult but not in adolescent mice

“…Control groups were injected with physiological saline (NaCl 0.9%), which was also used to dissolve the drugs. The doses of cocaine were selected on the basis of previous studies showing that 1 mg/kg is a threshold dose (Vidal-Infer et al, 2012;Arenas et al, 2014;Montagud-Romero et al, 2014) and that 25 mg/kg induces a strong CPP that is reinstated after priming with 12.5 mg/kg of cocaine ).…”

The novelty-seeking phenotype modulates the long-lasting effects of adolescent MDMA exposure

“…Head-dipping in the hole-board test has been proposed as a useful measure with which to examine the relationship between novelty-seeking and drug abuse [53]. Previous studies show that the hole-board test is more effective in identifying adolescent mice that will be sensitive to the conditioned rewarding effects of cocaine on the long-lasting effects of ethanol or cocaine [37][38][39]. The median was used in order to classify the mice as HNS versus LNS, as this is a standard measure when a set of data has been arranged in order of magnitude and is less affected by outliers.…”

“…Adolescent rodents display a drive to search for novel objects, environments, situations and stimuli [33][34][35][36]. We have previously demonstrated that sensitivity to the conditioned reinforcing effects of cocaine depends on the level of NS of the mice, with stronger responses being observed in high novelty seekers (HNS) [36,37]. Moreover, we have observed that the long-term effects of adolescent exposure to cocaine or ethanol are also modulated by the NS trait in mice; only HNS exposed to cocaine during adolescence presented CPP with non-effective doses of cocaine or MDMA [38].…”

“…In order to evaluate the propensity to explore a new environment in a free-choice procedure, early adolescent mice (PND 25) were tested in the hole-board task and classified as HNS or LNS depending on the number of dips they performed. We have previously used this test to predict which adolescent mice will be more sensitive to the conditioned rewarding effects of cocaine in the future [37]. HNS and LNS mice received 8 doses of MDMA over a 2-week period and, 3 weeks after the last dose -now in adulthood -their spontaneous and drug-induced behavior was evaluated.…”