Related Experiment Video
Updated: Jul 12, 2026
08:39
Operant Sensation Seeking in the Mouse
Published on: November 10, 2010
Mouse strain differences in opiate reward learning are explained by differences in anxiety, not reward or learning
C L Dockstader1, D van der Kooy
1Department of Anatomy and Cell Biology, University of Toronto, Toronto, Ontario, M5S 1A8 Canada. colleen.dockstader@utoronto.ca
Summary
129 mice require both drug and contextual cues for opiate motivation, unlike C57BL/6 mice. High anxiety levels may explain some observed deficits in 129 mice, not motivational issues.
Area of Science:
- Neuroscience
- Behavioral Genetics
Background:
- Gene-targeting techniques are crucial for studying motivation.
- 129 mice, used for creating knock-out models, have poorly understood behavioral phenotypes.
- C57BL/6 mice are well-characterized, but 129 mice require further investigation.
Purpose of the Study:
- To investigate opiate motivation in 129/SvJ and C57BL/6J mouse strains.
- To determine the conditions under which 129/SvJ mice exhibit motivated behavior toward opiates.
Main Methods:
- Comparative analysis of opiate-induced conditioned place preference in 129/SvJ and C57BL/6J mice.
- Assessment of drug substitution effects (pentobarbital, diazepam, saline, cocaine, naloxone) in 129/SvJ mice.
Main Results:
- 129/SvJ mice needed both drug and contextual cues for morphine conditioned place preference.
- C57BL/6J mice only required contextual cues for opiate place conditioning.
- Pentobarbital and diazepam, but not saline, cocaine, or naloxone, substituted for morphine in 129/SvJ mice.
Conclusions:
- Morphine possesses rewarding motivational valence in 129/SvJ mice.
- Anxiolytic properties of effective drugs may serve as critical interoceptive cues for 129/SvJ mice.
- High anxiety levels during retrieval, rather than sensory, learning, or motivational deficits, may explain some 129 mouse behavioral issues.
