The effects of cocaine on operant responding for food in several strains of mice

Abstract

The availability of numerous genetically homogenous mouse strains permits the analysis of genetic influences on behavior and also behavioral sensitivity (responsivity) to drugs of abuse. The current study was conducted to characterize discriminated operant responding for food in four inbred strains (Balb/cByJ, DBA/2J, C57BL/6J, SJL/J), an F1 Hybrid (C57BL/6xSJL), and one outbred strain (CD1) of mouse. The effect of cocaine on this operant behavior was also examined. Initially, all animals were trained to nosepoke for food on a continuous reinforcement schedule. The minimum response requirement for reinforcement was increased every 5 days until the animals were responding on an FR-15 schedule of reinforcement. All strains increased operant responding as the schedule of reinforcement was raised. However, significant differences in response rate and discrimination learning were observed among the various strains of mice. Cocaine administration reduced operant responding for food in Balb/cByJ, C57BL/6J, C57BL/6xSJL/J and CD1 mice at a dose of 15.0 mg/kg, whereas higher doses were required in DBA/2J mice (30.0 mg/kg) and SJL/J mice (56.0 mg/kg). These results suggest that operant performance and the effect of cocaine on this behavior is differentially influenced by genetic make-up.

Reinforcing effect for corn oil stimulus was concentration dependent in an operant task in mice

“…Moreover, the inbred strain of BALB/c is more sensitive to emulsified fat source (Intralipid) than C57BL/6J in a two-bottle preference test (Lewis et al, 2007). In addition, BALB/c mice made more response than C57BL/6J mice in operant responding for food pellet (Heyser et al, 1997). Therefore, the discrepancy between the results of the two experiments might come from the experimental methods and/or genetic difference.…”

Dopamine D1 Rather than D2 Receptor Agonists Disrupt Prepulse Inhibition of Startle in Mice

“…The lack of effect of quinpirole may represent a pharmacokinetic species difference between rats and mice, or a difference that is specific to the strains of mice examined here. There have been several reports of strain differences in mice in response to pharmacological manipulations (Heyser et al, 1997;Homanics et al, 1999;Miner, 1997;Schlussman et al, 1998). Here we report on two inbred strains of mice, but more extensive pharmacological studies including male and female inbred and outbred strains of mice may provide a better characterization of the effects of D2-family agonists like quinpirole and pergolide on PPI in mice.…”

Differential Acquisition of Lever Pressing in Inbred and Outbred Mice: Comparison of One-Lever and Two-Lever Procedures and Correlation With Differences in Locomotor Activity

“…The DBA strain is believed to be the first inbred mouse, created in 1909 by Clarence Little (Beck et al, 2000). The DBA/2J substrain was reported to be less sensitive to cocaine's disruptive effects on operant behavior (FR 15) than C57BL/6J, BALB/cByJ, and CD-1 mice (Heyser, McDonald, Beauchamp, Koob, & Gold, 1997). Mice of the 129/SvJ strain have been characterized as ''poor'' learners in the Morris water maze (see Crawley et al, 1997).…”