title: 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.
authors.affiliation: Research Institute on Addictions, University at Buffalo, SUNY, 1021 Main St., Buffalo, NY 14203, USA. agancarz@ria.buffalo.edu
authors.forename: Amy M
authors.initials: AM
authors.lastname: Gancarz
authors.forename: Michele A
authors.initials: MA
authors.lastname: San George
authors.forename: Lisham
authors.initials: L
authors.lastname: Ashrafioun
authors.forename: Jerry B
authors.initials: JB
authors.lastname: Richards
mesh_terms: D000818:Animals; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology*; D004777:Environment; D006185:Habituation, Psychophysiologic; D007206:Individuality; D007262:Infusions, Intravenous; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology*; D010775:Photic Stimulation; D011237:Predictive Value of Tests; D051381:Rats; D020318:Rats, Long-Evans; D012054:Reinforcement, Psychology; D012646:Self Administration
chemical_list: D000697:Central Nervous System Stimulants; D008694:Methamphetamine