Moving Matters: Assessing the Impact of Early Life Inactivity on Murine Behavior

Research Team

Introduction

Research Questions

Methods

Results/Findings and Discussion

Conclusions and Future Study

Acknowledgements

References

NACE Career Readiness Competencies

Research Compliance Protocols

Research Team

Grace Scott was mentored by Dr. Paul Reidy and graduate students Jackson Yeager and Arina Prikhodko. She was assisted by undergraduate researchers Amritesh Bali, Julia Beltran, and Ava Ward.

Grace Scott

Kinesiology and Pre-Medical Studies

Jackson Yeager

Kinesiology, Nutrition and Health. Master of Science, Exercise Science concentration

Arina Prikhodko

Kinesiology, Nutrition and Health. Master of Science, Exercise Science concentration

Amritesh Bali

Biology and Pre-Medical Studies

Julia Beltran

Biology

Ava Ward

Biology, Spanish, and Pre-Medical Studies with a minor in Nutrition

Paul T. Reidy

Department of Kinesiology, Nutrition, and Health

Introduction

In an overarching study, only the male mice were beginning to fight each other in their cages at around 1-4 months old
This raised the question of if the fighting was a stress response due to early-life treatment and if the females were more resilient
This study looks at the behavioral effects on mice (n=38) at 4 months old due to varying levels of early life treatment (3 to 5 weeks postnatal)
Treatment groups consist of:

Voluntary wheel runners (VWR) who have access to a larger cage and wheel their entire life. Early life activity (ELA) who have access to a larger cage and wheel for 2 weeks. Sedentary control (SED) who remain in an IVC cage their entire life. Small mouse cage (SMC) who live in condensed housing for 2 weeks. Hind-limb unloaded (HU) who have their back legs suspended for 2 weeks

Research Questions

Does early-life inactivty have a psychological impact on murine behavior?
Are female mice more resilient to stress/anxiety?

Methods

Approved under IACUC Protocol #1103_27
After strength/endurance testing (4 months), various behavioral tests were conducted

Open Field Test (OFT). Social Interaction Tests (SI): Social Novelty (SNT), Social Preference (SPT). Sucrose Preference (SP) using 1% sucrose solution and water for 24 hours

Two-Way ANOVA statistical analysis was performed, presented as Mean ± SEM by sex

Results/Findings and Discussion

Results

Open Field

In general, male mice spent more time in the center zone than female mice. No significant differences

Social Preference

Male mice spent more time investigating the new mouse, except VWR. No significant differences

Social Novelty

Male mice spent more time investigating the empty cup, except VWR. No significant differences

Sucrose Preference

No significant differences. Large amounts of variability

Discussion

Open Field

The male VWR mice spent the most time in the center, indicating that they were the most confident
Conversely, the HU mice spent the least amount of time in the center, indicating higher stress and anxiety levels

Social Preference

The mice show no preference for the empty cup or the mouse, indicating potential stress, as a healthy mouse would choose to interact with the other mouse

Social Novelty

SMC was the most curious in the novel mouse, while SED, and HU are essentially equal. VWR had the least interest. This is contradictory to prior hypotheses, as a healthy mouse exibits high amounts of curiosity

Sucrose Preference

There is not a strong preference seen for sucrose over water between sex groups. However, all mice drank more water than sucrose
Test would likely benefit from longer duration, increased sucrose concentration, and variability in the order of water bottles in their cage (right or left side

Sucrose Preference

$This bar graph, titled "Figure 1: Effect of early life activity on the ratio of sucrose solution drank vs water drank by sex," illustrates the results of a Sucrose Preference Test across five different treatment groups.Graph StructureY-Axis: Normalized Sucrose:Water Ratio (ranging from -0.1 to 0.4).X-Axis: Early Life Treatment groups (VWR, ELA, SED, SMC, and HU).Legend: Blue bars represent Male mice; pink bars represent Female mice.Visual Elements: Each bar includes an error bar (whiskers) representing variability (Mean $\pm$ SEM).Data Breakdown by GroupVWR (Voluntary Wheel Runners): Males hover around a 0.05 ratio. Females show a higher mean (~0.13) but feature an exceptionally large error bar, extending from below 0 to above 0.3, indicating massive individual variability in this group.ELA (Early Life Active): Both sexes show low preference, with males at ~0.04 and females at ~0.05.SED (Sedentary Control): Males show a slightly higher preference (~0.05) compared to females (~0.02).SMC (Small Mouse Cage): Females (~0.08) show a higher preference than males (~0.02).HU (Hind-limb Unloaded): Females (~0.09) show a higher preference than males (~0.03).$

Open Field

$This bar graph, titled "Figure 2. Effect of early life treatment on the amount of time (s) the mouse spends in the center zone by sex," displays results from the Open Field Test, a common measure of anxiety-like behavior in rodents.Graph StructureY-Axis: Time (s) in Mobile Center Zone, ranging from 0 to 800 seconds.X-Axis: Early Life Treatment groups: VWR (Voluntary Wheel Running), ELA (Early Life Active), SED (Sedentary), SMC (Small Mouse Cage), and HU (Hind-limb Unloaded).Legend: Blue bars represent Male mice; Pink bars represent Female mice.Visual Elements: Bars include error bars representing Mean $\pm$ SEM.Data Breakdown by GroupVWR (Voluntary Wheel Runners): Males spent the most time in the center (~450s), while females spent significantly less (~230s).ELA (Early Life Active): Males (~360s) again spent more time in the center than females (~170s).SED (Sedentary Control): This is the only group where females (~300s) spent more time in the center than males (~210s).SMC (Small Mouse Cage): Males spent ~330s in the center compared to females at ~190s.HU (Hind-limb Unloaded): Males spent ~270s in the center. Females in this group showed the lowest center time of the entire study (~90s).Key Observations & StatisticsTrends by Sex: In four out of five groups, male mice spent more time in the center zone than female mice, suggesting lower anxiety or higher "confidence" levels in those specific conditions.Statistical Markers: * The difference between Male VWR and Female VWR is noted with $p = 0.0657$.The difference between Male VWR and Male SED is noted with $p = 0.0801$.Both values are "approaching significance" (near the standard $p < 0.05$ threshold) but suggest that voluntary exercise has a notable impact on center-zone exploration for males compared to sedentary or female counterparts.Highest vs. Lowest: Male VWR mice were the most active in the center (highest confidence/lowest stress), while Female HU mice were the least active in the center (highest stress/anxiety).$

Social Preference

This bar graph, titled "Figure 3. Effect of early life activity on the ratio of time spent investigating the right cup vs the left cup," illustrates the results of the Social Preference Test. Graph Structure Y-Axis: Percentage of Time of Total Cup Investigations (ranging from 0% to 100%). X-Axis: Early Life Treatment groups: VWR, ELA, SED, SMC, and HU. Legend: Blue bars represent Male mice; Pink bars represent Female mice. Key Context: In this test, the left cup contained a mouse and the right cup was empty. A higher ratio indicates the mouse spent more time investigating the empty cup (suggesting lower social preference). Data Breakdown by Group VWR (Voluntary Wheel Runners): Both sexes show a nearly neutral preference, with males and females hovering around 55–58%. ELA (Early Life Active): Males show a high investigation of the empty cup (~72%), while females investigated it less than half the time (~46%). SED (Sedentary Control): Both sexes showed a strong preference for the empty cup, both reaching approximately 82–85%. SMC (Small Mouse Cage): Males showed a high preference for the empty cup (~80%), while females spent significantly less time there (~45%). HU (Hind-limb Unloaded): Males preferred the empty cup (~75%) more than females did (~59%).

Social Novelty

This bar graph, titled "Figure 4. Effect of early life activity on the ratio of time spent investigating the right cup vs the left cup," presents the results of the Social Novelty Test. Graph Structure Y-Axis: Percentage of Time of Total Cup Investigations (0% to 100%). X-Axis: Early Life Treatment groups: VWR, SED, SMC, and HU. (Note: The ELA group is not included in this specific figure). Legend: Blue bars represent Male mice; Pink bars represent Female mice. Key Context: In this phase of testing, the left cup contained a familiar mouse and the right cup contained a novel (new) mouse. A higher ratio indicates the subject spent more time investigating the novel mouse, which is generally interpreted as a sign of healthy curiosity. Data Breakdown by Group VWR (Voluntary Wheel Runners): This group showed the lowest interest in the novel mouse. Males were at approximately 36% and females at 41%. SED (Sedentary Control): Males showed a moderate preference for the novel mouse (~55%), while females showed less interest (~36%). SMC (Small Mouse Cage): This group exhibited the highest curiosity. Males spent roughly 71% of their time with the novel mouse, while females were at 50%. HU (Hind-limb Unloaded): Males were at approximately 52% and females at 42%.

Conclusions and Future Study

Conclusion

Overall, it seems that there was no significant affect on stress levels in the mice due to early life treatment. Howver, it does seem that all mice were stressed. It is possible that the timepoint of testing was too late. It may be beneficial to re-run the tests earlier into the fighting period

Future Study

This experiment strives to improve upon a potentially translatable small mouse-cage inactivity model by modulating housing density. We hope to determine to what degree early-life physical inactivity during postnatal development may decrease muscle strength and metabolic function, as well as gauge the impact it has on behavior. Goals include continued hands-on training in animal handling and new murine testing techniques, such as glucose tolerance testing and sophisticated muscle-force testing.

$The following is an image of poster presented at the 2026 Undergraduate Research Forum. This scientific poster, titled "Moving Matters: Assessing the Impact of Early Life Inactivity on Murine Behavior," presents research from Miami University regarding how early-life physical activity (or lack thereof) influences behavioral stress and social interaction in mice. Header & Authors Title: Moving Matters: Assessing the Impact of Early Life Inactivity on Murine Behavior Authors: Grace E. Scott, Jackson Yeager, Arina Prikhodko, Amritesh Bali, Julia Beltran, Ava Ward, Anna K. Radke, Paul T. Reidy. Affiliation: Miami University, College of Education, Health, and Society; Department of Kinesiology, Nutrition, and Health. Introduction & Hypotheses The study was prompted by observations of male mice fighting between 1–4 months of age. Researchers questioned if this was a stress response to early-life treatment and if females showed more resilience. Subjects: n=38 mice, tested at 4 months old. Objective: To observe behavioral effects of varying activity levels from 3 to 5 weeks postnatal. Experimental Groups (Treatment) VWR (Voluntary Wheel Runners): Access to a large cage and wheel for their entire life. ELA (Early Life Active): Access to a cage and wheel for only 2 weeks (early life). SED (Sedentary Control): Remained in a standard IVC cage for their entire life. SMC (Small Mouse Cage): Housed in condensed housing for 2 weeks. HU (Hind-limb Unloaded): Back legs suspended for 2 weeks to simulate extreme inactivity. Methods & Activity Timeline The research followed IACUC Protocol #1103_27. After strength/endurance testing at 4 months, mice underwent: Open Field Test (OFT) Social Interaction Tests (Social Preference & Social Novelty) Sucrose Preference Test (SPT) Analysis: Two-Way ANOVA, presented as Mean $\pm$ SEM by sex. Behavioral Test Results 1. Open Field Test (Anxiety/Confidence) Measurement: Time spent in the "Center Zone" (a virtual square in an empty box). Findings: Male VWR mice spent the most time in the center (highest confidence). HU (Hind-limb Unloaded) mice spent the least time (highest stress/anxiety). In general, males were more active in the center than females. 2. Social Preference Test Measurement: Ratio of time investigating a "mouse cup" vs. an empty cup. Findings: Most mice showed no significant preference between the empty cup and the mouse, which was unexpected, as healthy mice typically prefer social interaction. 3. Social Novelty Test Measurement: Ratio of time investigating a "novel mouse" vs. a familiar mouse. Findings: SMC (Small Cage) mice were the most curious. VWR mice showed the least interest in novelty, contradicting the hypothesis that active mice would exhibit higher curiosity. 4. Sucrose Preference Test (Anhedonia/Depression) Measurement: Ratio of sucrose solution consumed vs. plain water. Findings: No significant differences between groups, though all mice consumed more sucrose than water. There was high variability in the data. Discussion & Conclusion Key Insight: While early-life treatment didn't show a statistically significant impact on long-term stress levels, the researchers noted that all mice appeared stressed. Limitation: The testing may have occurred too late (4 months). Future studies may benefit from testing earlier during the "fighting period" (1–4 months) and increasing sucrose concentrations for more definitive results. Professional Development & Acknowledgements NACE Competencies: The project involved peer communication, leadership development, and navigating new software. Funding: NIH NIAMS 1R15AR084182-01 to Paul T. Reidy. Attribution: Photos and tables were generated by Gemini AI; graphs were generated in GraphPad Prism.$

Acknowledgements

Funding was provided by the NIH NIAMS 1R15AR084182-01 to Paul T. Reidy.

References

Photos and table generated by Gemini AI.

Graphs generated in GraphPad Prism

NACE Career Readiness Competencies

Every test required clear communication between peers
Developed leadership skills through scheduling weekly testing
Expanded technological abilities through navigating new software

Research Compliance Protocols

Approved under IACUC Protocol #1103_27

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