title: Artificial light at night alters delayed-type hypersensitivity reaction in response to acute stress in Siberian hamsters.
abstract: Several physiological and behavioral processes rely on precisely timed light information derived from the natural solar cycle. Using this information, traits have adapted to allow individuals within specific niches to optimize survival and reproduction, but urbanization by humans has significantly altered natural habitats. Nighttime light exposure alters immune function in several species, which could lead to decreased fitness or survival, particularly in the face of an environmental challenge. We exposed male Siberian hamsters (Phodopus sungorus) to five lux of light at night for four weeks, and then administered six hours of acute restraint stress. Delayed-type hypersensitivity (DTH) response was assessed immediately following stress. Acute restraint increased the DTH reaction in dark nights, but exposure to nighttime light prevented this response. Exposure to light at night prolonged the DTH response in non-stressed control hamsters. These results suggest that light pollution may significantly alter physiological responses in Siberian hamsters, particularly in response to a salient environmental challenge such as stress.
authors.affiliation: Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH, United States. Electronic address: Bedrosian.2@osu.edu.
authors.forename: Tracy A
authors.initials: TA
authors.lastname: Bedrosian
authors.forename: Taryn G
authors.initials: TG
authors.lastname: Aubrecht
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Kaugars
authors.forename: Zachary M
authors.initials: ZM
authors.lastname: Weil
authors.forename: Randy J
authors.initials: RJ
authors.lastname: Nelson
mesh_terms: D000818:Animals; D006224:Cricetinae; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D008027:Light; D008297:Male; D017111:Phodopus; D013312:Stress, Physiological / Q000276:immunology*; D013997:Time Factors
keywords: Immune function; Light pollution; Phodopus sungorus; Restraint stress