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Updated: Feb 23, 2026
Morris Water Maze Test: Optimization for Mouse Strain and Testing Environment
Published on: June 22, 2015
Adapted Morris Water Maze protocol to prevent interference from confounding motor deficits on cognitive functioning
Mattias De Coninck1, Debby Van Dam1,2, Chris Van Ginneken3
1a Laboratory for Neurochemistry and Behaviour , Institute Born-Bunge, University of Antwerp , Wilrijk , Belgium.
Abstract:
Purpose/aim of the study: Cognitive functioning in the Morris Water Maze (MWM) is assumed to be reflected by path length. In this study, the interference of motor deficits, as a confounding factor on cognitive functioning, was assessed by means of a lateralization study with hemicerebellectomized (HCX) mice. This model is characterized by motor deficits restricted to the lesion side, allowing comparison within the model itself (left vs. right), rather than the effect of the manipulation on this measure (experimental vs. control).
Materials And Methods:
Spatial learning was assessed after left or right hemicerebellectomy in adult mice by means of two MWM designs in which the location of the starting positions was altered for one condition in the adapted (Adap) MWM experiment, hypothesizing that motor impairments ipsilateral to the lesion side result in a difference in path length.
Results:
When the starting positions were equal for both conditions in the traditional (Trad) MWM experiment, path length during the acquisition phase and spatial memory were more affected for the left HCX, while these effects disappeared after mirroring the starting positions in the Adap MWM, implying that motor phenotype and corresponding increase in task difficulty are responsible for the contradictory results in the Trad MWM experiment.
Conclusion:
The differences found in the latter experiment were circumvented in the adapted MWM protocol, and therefore, excluding the motor deficit as a confounding factor on cognitive MWM parameters.
Insights
Motor deficits in hemicerebellectomized (HCX) mice can confound Morris Water Maze (MWM) cognitive assessments. An adapted MWM protocol successfully excluded motor impairments as a confounding factor in spatial learning.
Area of Science:
- Neuroscience
- Behavioral Neuroscience
Background:
- The Morris Water Maze (MWM) is a common tool for assessing spatial learning and memory.
- Motor deficits can significantly confound MWM results, making it difficult to isolate cognitive effects.
- Hemicerebellectomy (HCX) in mice provides a model with lateralized motor deficits.
Purpose of the Study:
- To investigate the impact of motor deficits on cognitive functioning in the MWM.
- To assess the confounding effect of motor deficits in hemicerebellectomized (HCX) mice using a lateralized study.
- To develop and validate an adapted MWM protocol that mitigates the influence of motor impairments.
Main Methods:
- Spatial learning was evaluated in adult mice after left or right hemicerebellectomy (HCX).
- Two MWM designs were employed: a traditional (Trad) MWM and an adapted (Adap) MWM with altered starting positions.
- Path length was used as the primary measure to assess spatial learning and the influence of motor deficits.
Main Results:
- In the Trad MWM, left HCX mice showed impaired spatial learning and memory compared to controls.
- These deficits observed in the Trad MWM disappeared in the Adap MWM when starting positions were mirrored.
- The findings imply that motor phenotype and increased task difficulty, not cognitive deficits alone, contributed to the results in the Trad MWM.
Conclusions:
- Motor impairments in HCX mice can confound MWM performance, leading to inaccurate assessments of cognitive function.
- The adapted MWM protocol effectively circumvents motor deficits as a confounding factor.
- This adapted MWM approach allows for a more accurate evaluation of cognitive MWM parameters, excluding motor influences.
