Locomotor activity in a novel environment predicts both responding for a visual stimulus and self-administration of a low dose of methamphetamine in rats

Abstract

There is evidence that visual stimuli used to signal drug delivery in self-administration procedures have primary reinforcing properties, and that drugs of abuse enhance the reinforcing properties of such stimuli. Here, we explored the relationships between locomotor activity, responding for a visual stimulus, and self-administration of methamphetamine (METH). Rats were classified as high or low responders based on activity levels in a novel locomotor chamber and were subsequently tested for responding to produce a visual stimulus followed by self-administration of a low dose of METH (0.025 mg/kg/infusion) paired with the visual stimulus. High responder rats responded more for the visual stimulus than low responder rats indicating that the visual stimulus was reinforcing and that operant responding for a visual stimulus has commonalities with locomotor activity in a novel environment. Similarly, high responder rats responded more for METH paired with a visual stimulus than low responder rats. Because of the reinforcing properties of the visual stimulus, it was not possible to determine if the rats were responding to produce the visual stimulus, METH or the combination. We speculate that responding to produce sensory reinforcers may be a measure of sensation seeking. These results indicate that visual stimuli have unconditioned reinforcing effects which may have a significant role in acquisition of drug self-administration, a role that is not yet well understood.

Novel Cues Reinstate Cocaine-Seeking Behavior and Induce Fos Protein Expression as Effectively as Conditioned Cues

“…By contrast, the tone cue appeared to elicit slightly greater responding during sucrose training. These findings are curious, but this difference could be due to the ability of psychostimulants to increase responding for visual stimuli (Caggiula et al, 2002;Deroche-Gamonet et al, 2002;Donny et al, 2003;Gancarz et al, 2011;Palmatier et al, 2006;Winterbauer and Balleine, 2007) and amplify sensitivity to acoustic stimuli (Davis, 1985;Davis et al, 1975), thereby enhancing the initial reinforcing and/or aversive properties of the light and tone cues, respectively (Baron and Kish, 1962). Regardless, our cue modality effects are consistent with the sensory reinforcement literature.…”

Individual Differences and Social Influences on the Neurobehavioral Pharmacology of Abused Drugs

“…Since the initial report by Piazza et al (1989), several studies have confirmed that HR rats show increased amphetamine-induced activity (Bevins et al, 1997) and amphetamine self-administration (Piazza et al, 1990(Piazza et al, , 2000Pierre and Vezina, 1997;Klebaur et al, 2001a;Cain et al, 2005Cain et al, , 2006Cain et al, , 2008 compared with LR rats. The differences between HR and LR rats in amphetamine self-administration are similar for both males and females (Klebaur et al, 2001a), and these individual differences generalize to other stimulant drugs, including cocaine (Mantsch et al, 2001;Sell et al, 2005;Kabbaj, 2006;Belin et al, 2008Belin et al, , 2011Walker et al, 2009) and methamphetamine (Bevins and Peterson, 2004;Gancarz et al, 2011). Nicotine self-administration also is greater in HR rats than in LR rats (Suto et al, 2001), although these individual differences may not occur in nicotine-induced hyperactivity .…”

“…For example, maintenance of amphetamine self-administration is disrupted by novel stimuli, and this disruption is greater in HR rats than it is in LR rats (Cain et al, 2004). HR rats also show more responding than LR rats to earn novel visual stimuli (cue light illumination; Gancarz et al, 2011). These latter results are important because drug self-administration studies often use cue light illumination to signal the drug infusion or a time-out period (no drug availability) after the infusion.…”

“…More recently, operant conditioning measures of novelty seeking have been used to predict individual differences in sucrose self-administration in mice (Olsen and Winder, 2010). This measure of novelty seeking overlaps to some extent with the novelty responder test, as HR rats respond more for a novel visual reinforcer compared with LR rats (Gancarz et al, 2011).…”

Huperzine A inhibits immediate addictive behavior but not behavioral sensitization following repeated morphine administration in rats

“…Prior to the study experiments, animals were provided adaptive feeding for 7 days. A previous study suggested that there were individual differences in the initial locomotor response to a novel environment in rats (28). Therefore, the adaptive feeding may make rats familiar with the test environment in advance and avoid the effect of a novel environment on locomotor activity.…”