Source Paper
Hydrogen‐Mediated Activation of the Nrf2/HO‐1 Signaling Pathway Improves Cognitive Impairment in Sleep‐Deprived Mice
Xiao Q, Zhou S, Tang B, Zhu Y
CNS Neurosci Ther • 2026
Novel Object Recognition Test
Objective: To assess recognition memory by measuring the preference for exploring a novel object versus a familiar object
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Protocol Steps
Day 1 preparation
Bring mice to testing room and allow acclimatization for at least 30 minutes
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“Mice were brought to the testing room and acclimatized for ≥ 30 min”
Object placement
Place two identical objects in arena corners, 6 cm from adjacent walls, secured with double-sided tape
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“positioned 6 cm from adjacent walls in two non‐release corners”
Training session
Place each mouse facing release-corner wall and allow free exploration of arena and objects for 5 minutes
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“Each mouse was placed facing a release‐corner wall and permitted to freely explore the arena and objects for 5 min”
Inter-trial interval
Wait 20 minutes between sessions
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“After a 20‐min inter‐trial interval”
Arena cleaning
Clean arena thoroughly with 70% ethanol to remove odor cues
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“the arena was cleaned thoroughly with 70% ethanol to remove odor cues”
Day 2 object replacement
Replace one familiar object with a novel object, fixed similarly
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“One familiar object was exchanged for a novel object, fixed similarly”
Testing session
Place mouse facing wall and allow 5 minutes exploration
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“Each mouse was again introduced facing the wall and given 5 min exploration”
Data calculation
Calculate NOR index using the formula: (Time exploring novel object - Time exploring familiar object) / Total exploration time × 100%
View evidence from paper
“Time exploring novel object − Time exploring familiar object / Total exploration time × 100 %”