title: Methodological considerations for measuring spontaneous physical activity in rodents.
abstract: When exploring biological determinants of spontaneous physical activity (SPA), it is critical to consider whether methodological factors differentially affect rodents and the measured SPA. We determined whether acclimation time, sensory stimulation, vendor, or chamber size affected measures in rodents with varying propensity for SPA. We used principal component analysis to determine which SPA components (ambulatory and vertical counts, time in SPA, and distance traveled) best described the variability in SPA measurements. We compared radiotelemetry and infrared photobeams used to measure SPA and exploratory activity. Acclimation time, sensory stimulation, vendor, and chamber size independently influenced SPA, and the effect was moderated by the propensity for SPA. A 24-h acclimation period prior to SPA measurement was sufficient for habituation. Principal component analysis showed that ambulatory and vertical measurements of SPA describe different dimensions of the rodent's SPA behavior. Smaller testing chambers and a sensory attenuation cubicle around the chamber reduced SPA. SPA varies between rodents purchased from different vendors. Radiotelemetry and infrared photobeams differ in their sensitivity to detect phenotypic differences in SPA and exploratory activity. These data highlight methodological considerations in rodent SPA measurement and a need to standardize SPA methodology.
authors.affiliation: Department of Nutritional Sciences, University of Arizona, Tucson, Arizona; Minneapolis VA Health Care System, Minneapolis, Minnesota; Minnesota Obesity Center, University of Minnesota, Saint Paul, Minnesota; Department of Food Science and Nutrition, University of Minnesota, Saint Paul, Minnesota; teskeja@email.arizona.edu.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Teske
authors.affiliation: Center for Integrative Medicine and Innovative Science, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile;
authors.forename: Claudio E
authors.initials: CE
authors.lastname: Perez-Leighton
authors.affiliation: Minneapolis VA Health Care System, Minneapolis, Minnesota; Minnesota Obesity Center, University of Minnesota, Saint Paul, Minnesota; Department of Food Science and Nutrition, University of Minnesota, Saint Paul, Minnesota; Department of Medicine, University of Minnesota, Minneapolis, Minnesota; and.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Billington
authors.affiliation: Minneapolis VA Health Care System, Minneapolis, Minnesota; Geriatric Research Education and Clinical Center, Minneapolis, Minnesota; Minnesota Obesity Center, University of Minnesota, Saint Paul, Minnesota; Department of Food Science and Nutrition, University of Minnesota, Saint Paul, Minnesota; Department of Medicine, University of Minnesota, Minneapolis, Minnesota; and Graduate Program in Neuroscience, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Kotz
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D007259:Infrared Rays; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D009043:Motor Activity / Q000502:physiology*; D025341:Principal Component Analysis / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D013686:Telemetry
keywords: brain; environmental enrichment; locomotor; obesity; reward; sleep