Identification of a lipid-rich depot in the orbital cavity of the 13-lined ground squirrel
| Autor: | Amanda D. V. MacCannell, James F. Staples, Charles A. McKenzie, Glenn J. Tattersall, Kevin J. Sinclair |
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| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
Hibernation medicine.medical_specialty Physiology Depot 030310 physiology Adipose tissue Aquatic Science 010603 evolutionary biology 01 natural sciences 03 medical and health sciences Internal medicine Brown adipose tissue medicine Uncoupling protein Ground squirrel Molecular Biology Ecology Evolution Behavior and Systematics 0303 health sciences biology Chemistry Torpor biology.organism_classification Thermogenin Endocrinology medicine.anatomical_structure Insect Science Animal Science and Zoology |
| Zdroj: | Journal of Experimental Biology. |
| ISSN: | 1477-9145 0022-0949 |
| DOI: | 10.1242/jeb.195750 |
| Popis: | We discovered a previously undescribed orbital lipid depot in the thirteen-lined ground squirrel during the first ever magnetic resonance image (MRI) of this common experimental model of mammalian hibernation. In animals housed at constant ambient temperatures (5°C or 25°C, 12 h:12 h light:dark photoperiod), the volume of this depot increased in the autumn and decreased in the spring, suggesting an endogenous circannual pattern. Water-fat MRI revealed that throughout the year this depot is composed of ∼40% lipid, similar to brown adipose tissue (BAT). During arousal from torpor, thermal images showed higher surface temperatures near this depot before the rest of the head warmed, suggesting a thermoregulatory function. This depot, however, does not contain uncoupling protein 1, a BAT biomarker, or uncoupling protein 3. Histology shows blood vessels in close proximity to each other, suggesting it may serve as a vascular rete, perhaps to preferentially warm the eye and brain during arousals. |
| Databáze: | OpenAIRE |
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