Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2009 Jan-Feb;31(1):18-25.
doi: 10.1016/j.ntt.2008.09.002. Epub 2008 Sep 17.

Abuse pattern of toluene exposure alters mouse behavior in a waiting-for-reward operant task

Affiliations

Abuse pattern of toluene exposure alters mouse behavior in a waiting-for-reward operant task

Scott E Bowen et al. Neurotoxicol Teratol. 2009 Jan-Feb.

Abstract

Inhaling solvents for recreational purposes continues to be a world-wide public health concern. Toluene, a volatile solvent in many abused products, adversely affects the central nervous system. However, the long-term neurobehavioral effects of exposure to high-concentration, binge patterns typical of toluene abuse remain understudied. We studied the behavioral effects of repeated toluene exposure on cognitive function following binge toluene exposure on behavioral impulse control in Swiss Webster mice using a "wait-for-reward" operant task. Mice were trained on a fixed-ratio (FR) schedule using sweetened milk as a reward. Upon achieving FR15, a wait component was added which delivered free rewards in the absence of responses at increasing time intervals (2s, 4s, 6s, etc...). Mice continued to receive free rewards until they pressed a lever that reinstated the FR component (FR Reset). Once proficient in the FR-Wait task, mice were exposed to either 1000 ppm, 3600 ppm or 6000 ppm toluene, or 0ppm (air controls) for 30 min per day for 40 days. To avoid acute effects of toluene exposure, behavior was assessed approximately 22-23 h later. Repeated toluene exposure decreased response rates, the number of FR resets, and increased mean wait time, resulting in a higher response-to-reinforcer ratio than exhibited by controls. Mice receiving the higher exposure level (6000 ppm) showed a dramatic decrease in the number of rewards received, which was reversed when toluene exposure ceased. Mice receiving the lower exposure level (1000 ppm) showed little change in the number of rewards. These results indicate that repeated binge exposures to high concentrations of toluene can significantly interfere with performance as measured by a waiting-for-reward task, suggesting a significant impact on cognitive and/or psychomotor function.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Diagram of “waiting for reward” paradigm (adapted from Brockel and Cory-Slechta, 1998).
Figure 2
Figure 2
Effects of air and toluene exposure on the number of “free” rewards earned both during exposure (left panel) and during recovery (right panel). Each point represents the mean % of control (± SEM) of rewards earned during a 30-min session collapsed in four day blocks. N = 10 mice for each group.
Figure 3
Figure 3
Effects of air and toluene exposure on the number of FR resets during exposure (left panel) and during recovery (right panel). Each point represents the mean % of control (± SEM) of FR resets during a 30-min session collapsed in four day blocks. N = 10 mice for each group.
Figure 4
Figure 4
Effects of air and toluene exposure on the mean wait time both during exposure (left panel) and during recovery (right panel). Each point represents the mean % of control (± SEM) of the average of the individual waiting times prior to each FR reset collapsed in four day blocks. N = 10 mice for each group.
Figure 5
Figure 5
Effects of air and toluene exposure on response rates both during exposure (left panel) and during recovery (right panel). Each point represents the mean % of control (± SEM) of the number of responses/second during a 30-min session collapsed in four day blocks. N = 10 mice for each group.
Figure 6
Figure 6
Effects of air and toluene exposure on the number of responses per reward earned both during exposure (left panel) and during recovery (right panel). Each point represents the mean % of control (± SEM) of the number of responses per reward earned during a 30-min session collapsed in four day blocks. N = 10 mice for each group.

References

    1. Boor JW, Hurtig HI. Persistent cerebellar ataxia after exposure to toluene. Ann Neurol. 1977;2:440–2. - PubMed
    1. Bowen SE. Increases in amphetamine-like discriminative stimulus effects of the abused inhalant toluene in mice. Psychopharmacology. 2006;186:517–24. - PubMed
    1. Bowen SE, Balster RL. A direct comparison of inhalant effects on locomotor activity and schedule-controlled behavior in mice. Exp Clin Psychopharmacol. 1998;6:235–47. - PubMed
    1. Bowen SE, Balster RL. Tolerance and sensitization to inhaled 1,1,1-trichloroethane in mice: results from open-field behavior and a functional observational battery. Psychopharmacology. 2006;185:405–15. - PubMed
    1. Bowen SE, Batis JC, Mohammadi MH, Hannigan JH. Abuse pattern of gestational toluene exposure and early postnatal development in rats. Neurotoxicol Teratol. 2005;27:105–16. - PubMed

Publication types