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Using the Morris water maze to assess spatial learning and memory in weanling mice.

Barnhart CD, Yang D, Lein PJ - PLoS ONE (2015)

Bottom Line: However, Morris water maze studies with mice have principally been performed using adult animals, which preclude studies of critical neurodevelopmental periods when the cellular and molecular substrates of learning and memory are formed.While weanling rats have been successfully trained in the Morris water maze, there have been few attempts to test weanling mice in this behavioral paradigm even though mice offer significant experimental advantages because of the availability of many genetically modified strains.These findings demonstrate that the Morris water maze can be used to assess spatial learning and memory in weanling mice, providing a potentially powerful experimental approach for examining the influence of genes, environmental factors and their interactions on the development of learning and memory.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA, United States of America.

ABSTRACT
Mouse models have been indispensable for elucidating normal and pathological processes that influence learning and memory. A widely used method for assessing these cognitive processes in mice is the Morris water maze, a classic test for examining spatial learning and memory. However, Morris water maze studies with mice have principally been performed using adult animals, which preclude studies of critical neurodevelopmental periods when the cellular and molecular substrates of learning and memory are formed. While weanling rats have been successfully trained in the Morris water maze, there have been few attempts to test weanling mice in this behavioral paradigm even though mice offer significant experimental advantages because of the availability of many genetically modified strains. Here, we present experimental evidence that weanling mice can be trained in the Morris water maze beginning on postnatal day 24. Maze-trained weanling mice exhibit significant improvements in spatial learning over the training period and results of the probe trial indicate the development of spatial memory. There were no sex differences in the animals' performance in these tasks. In addition, molecular biomarkers of synaptic plasticity are upregulated in maze-trained mice at the transcript level. These findings demonstrate that the Morris water maze can be used to assess spatial learning and memory in weanling mice, providing a potentially powerful experimental approach for examining the influence of genes, environmental factors and their interactions on the development of learning and memory.

No MeSH data available.


Related in: MedlinePlus

Weanling mice exhibit spatial learning in the Morris water maze (MWM).Spatial learning was assessed as a function of training day with respect to the following parameters: (A) escape latency, (B) percentage of time spent in the target quadrant, and (C) percentage of total path length spent in the target quadrant. Data are presented as the mean ± SEM (n = 16 animals). Since sex differences were not identified for any of the behavioral parameters shown in this Fig., data from males and females were combined to calculate mean values. Significantly different from training d 1 (A) or d 2 (B and C) at ap < 0.05, bp < 0.01, cp < 0.001 as determined using repeated measures ANOVA with LSD post hoc test. Effect sizes: partial η2 for latency = 0.31, partial η2 for % time = 0.21; partial η2 for % path length = 0.17. Power: 99% for latency, 94% for % time, 84% for % path length. Note that escape latency was the only data collected on the first day of training because of a computer malfunction in collecting data on the first training day.
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pone.0124521.g001: Weanling mice exhibit spatial learning in the Morris water maze (MWM).Spatial learning was assessed as a function of training day with respect to the following parameters: (A) escape latency, (B) percentage of time spent in the target quadrant, and (C) percentage of total path length spent in the target quadrant. Data are presented as the mean ± SEM (n = 16 animals). Since sex differences were not identified for any of the behavioral parameters shown in this Fig., data from males and females were combined to calculate mean values. Significantly different from training d 1 (A) or d 2 (B and C) at ap < 0.05, bp < 0.01, cp < 0.001 as determined using repeated measures ANOVA with LSD post hoc test. Effect sizes: partial η2 for latency = 0.31, partial η2 for % time = 0.21; partial η2 for % path length = 0.17. Power: 99% for latency, 94% for % time, 84% for % path length. Note that escape latency was the only data collected on the first day of training because of a computer malfunction in collecting data on the first training day.

Mentions: Escape latency decreased over the 7 d training period (Fig 1A). Repeated-measures one-way ANOVA identified a significant reduction in escape latency with training (F(6,90) = 6.58, p < 0.0001). Weanlings also spent a significantly increased percentage of swimming time (F(5,75) = 4.08, p = 0.003) and path length (F(5,75) = 3.03, p = 0.02) in the target quadrant over the course of training (Fig 1B and 1C). The effect sizes for these parameters ranged between medium and large (for latency, partial η2 = 0.31; for % time, partial η2 = 0.21; for % path length, partial η2 = 0.17). The power calculated by SPSS was 99% for latency, 94% for % time, and 84% for % path length.


Using the Morris water maze to assess spatial learning and memory in weanling mice.

Barnhart CD, Yang D, Lein PJ - PLoS ONE (2015)

Weanling mice exhibit spatial learning in the Morris water maze (MWM).Spatial learning was assessed as a function of training day with respect to the following parameters: (A) escape latency, (B) percentage of time spent in the target quadrant, and (C) percentage of total path length spent in the target quadrant. Data are presented as the mean ± SEM (n = 16 animals). Since sex differences were not identified for any of the behavioral parameters shown in this Fig., data from males and females were combined to calculate mean values. Significantly different from training d 1 (A) or d 2 (B and C) at ap < 0.05, bp < 0.01, cp < 0.001 as determined using repeated measures ANOVA with LSD post hoc test. Effect sizes: partial η2 for latency = 0.31, partial η2 for % time = 0.21; partial η2 for % path length = 0.17. Power: 99% for latency, 94% for % time, 84% for % path length. Note that escape latency was the only data collected on the first day of training because of a computer malfunction in collecting data on the first training day.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401674&req=5

pone.0124521.g001: Weanling mice exhibit spatial learning in the Morris water maze (MWM).Spatial learning was assessed as a function of training day with respect to the following parameters: (A) escape latency, (B) percentage of time spent in the target quadrant, and (C) percentage of total path length spent in the target quadrant. Data are presented as the mean ± SEM (n = 16 animals). Since sex differences were not identified for any of the behavioral parameters shown in this Fig., data from males and females were combined to calculate mean values. Significantly different from training d 1 (A) or d 2 (B and C) at ap < 0.05, bp < 0.01, cp < 0.001 as determined using repeated measures ANOVA with LSD post hoc test. Effect sizes: partial η2 for latency = 0.31, partial η2 for % time = 0.21; partial η2 for % path length = 0.17. Power: 99% for latency, 94% for % time, 84% for % path length. Note that escape latency was the only data collected on the first day of training because of a computer malfunction in collecting data on the first training day.
Mentions: Escape latency decreased over the 7 d training period (Fig 1A). Repeated-measures one-way ANOVA identified a significant reduction in escape latency with training (F(6,90) = 6.58, p < 0.0001). Weanlings also spent a significantly increased percentage of swimming time (F(5,75) = 4.08, p = 0.003) and path length (F(5,75) = 3.03, p = 0.02) in the target quadrant over the course of training (Fig 1B and 1C). The effect sizes for these parameters ranged between medium and large (for latency, partial η2 = 0.31; for % time, partial η2 = 0.21; for % path length, partial η2 = 0.17). The power calculated by SPSS was 99% for latency, 94% for % time, and 84% for % path length.

Bottom Line: However, Morris water maze studies with mice have principally been performed using adult animals, which preclude studies of critical neurodevelopmental periods when the cellular and molecular substrates of learning and memory are formed.While weanling rats have been successfully trained in the Morris water maze, there have been few attempts to test weanling mice in this behavioral paradigm even though mice offer significant experimental advantages because of the availability of many genetically modified strains.These findings demonstrate that the Morris water maze can be used to assess spatial learning and memory in weanling mice, providing a potentially powerful experimental approach for examining the influence of genes, environmental factors and their interactions on the development of learning and memory.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA, United States of America.

ABSTRACT
Mouse models have been indispensable for elucidating normal and pathological processes that influence learning and memory. A widely used method for assessing these cognitive processes in mice is the Morris water maze, a classic test for examining spatial learning and memory. However, Morris water maze studies with mice have principally been performed using adult animals, which preclude studies of critical neurodevelopmental periods when the cellular and molecular substrates of learning and memory are formed. While weanling rats have been successfully trained in the Morris water maze, there have been few attempts to test weanling mice in this behavioral paradigm even though mice offer significant experimental advantages because of the availability of many genetically modified strains. Here, we present experimental evidence that weanling mice can be trained in the Morris water maze beginning on postnatal day 24. Maze-trained weanling mice exhibit significant improvements in spatial learning over the training period and results of the probe trial indicate the development of spatial memory. There were no sex differences in the animals' performance in these tasks. In addition, molecular biomarkers of synaptic plasticity are upregulated in maze-trained mice at the transcript level. These findings demonstrate that the Morris water maze can be used to assess spatial learning and memory in weanling mice, providing a potentially powerful experimental approach for examining the influence of genes, environmental factors and their interactions on the development of learning and memory.

No MeSH data available.


Related in: MedlinePlus