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Exposure to artificial light at night alters innate immune response in wild great tit nestlings

Ziegler, Ann-Kathrin LU ; Watson, Hannah LU orcid ; Hegemann, Arne LU ; Meitern, Richard ; Canoine, Virginie ; Nilsson, Jan-Åke LU and Isaksson, Caroline LU orcid (2021) In Journal of Experimental Biology 224(10).
Abstract
The large-scale impact of urbanization on wildlife is rather well documented; however, the mechanisms underlying the effects of urban environments on animal physiology and behaviour are still poorly understood. Here, we focused on one major urban pollutant – artificial light at night (ALAN) – and its effects on the capacity to mount an innate immune response in wild great tit (Parus major) nestlings. Exposure to ALAN alters circadian rhythms of physiological processes, by disrupting the nocturnal production of the hormone melatonin. Nestlings were exposed to a light source emitting 3 lx for seven consecutive nights. Subsequently, nestlings were immune challenged with a lipopolysaccharide injection, and we measured haptoglobin and nitric... (More)
The large-scale impact of urbanization on wildlife is rather well documented; however, the mechanisms underlying the effects of urban environments on animal physiology and behaviour are still poorly understood. Here, we focused on one major urban pollutant – artificial light at night (ALAN) – and its effects on the capacity to mount an innate immune response in wild great tit (Parus major) nestlings. Exposure to ALAN alters circadian rhythms of physiological processes, by disrupting the nocturnal production of the hormone melatonin. Nestlings were exposed to a light source emitting 3 lx for seven consecutive nights. Subsequently, nestlings were immune challenged with a lipopolysaccharide injection, and we measured haptoglobin and nitric oxide levels pre- and post-injection. Both haptoglobin and nitric oxide are important markers for innate immune function. We found that ALAN exposure altered the innate immune response, with nestlings exposed to ALAN having lower haptoglobin and higher nitric oxide levels after the immune challenge compared with dark-night nestlings. Unexpectedly, nitric oxide levels were overall lower after the immune challenge than before. These effects were probably mediated by melatonin, as ALAN-treated birds had on average 49% lower melatonin levels than the dark-night birds. ALAN exposure did not have any clear effects on nestling growth. This study provides a potential physiological mechanism underlying the documented differences in immune function between urban and rural birds observed in other studies. Moreover, it gives evidence that ALAN exposure affects nestling physiology, potentially causing long-term effects on physiology and behaviour, which ultimately can affect their fitness. (Less)
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author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Experimental Biology
volume
224
issue
10
article number
239350
pages
10 pages
publisher
The Company of Biologists Ltd
external identifiers
  • pmid:33771912
  • scopus:85106892958
ISSN
1477-9145
DOI
10.1242/jeb.239350
language
English
LU publication?
yes
id
0615541a-c6ea-44c5-af5e-4317acf4636e
date added to LUP
2021-07-01 12:12:05
date last changed
2024-09-21 22:09:14
@article{0615541a-c6ea-44c5-af5e-4317acf4636e,
  abstract     = {{The large-scale impact of urbanization on wildlife is rather well documented; however, the mechanisms underlying the effects of urban environments on animal physiology and behaviour are still poorly understood. Here, we focused on one major urban pollutant – artificial light at night (ALAN) – and its effects on the capacity to mount an innate immune response in wild great tit (Parus major) nestlings. Exposure to ALAN alters circadian rhythms of physiological processes, by disrupting the nocturnal production of the hormone melatonin. Nestlings were exposed to a light source emitting 3 lx for seven consecutive nights. Subsequently, nestlings were immune challenged with a lipopolysaccharide injection, and we measured haptoglobin and nitric oxide levels pre- and post-injection. Both haptoglobin and nitric oxide are important markers for innate immune function. We found that ALAN exposure altered the innate immune response, with nestlings exposed to ALAN having lower haptoglobin and higher nitric oxide levels after the immune challenge compared with dark-night nestlings. Unexpectedly, nitric oxide levels were overall lower after the immune challenge than before. These effects were probably mediated by melatonin, as ALAN-treated birds had on average 49% lower melatonin levels than the dark-night birds. ALAN exposure did not have any clear effects on nestling growth. This study provides a potential physiological mechanism underlying the documented differences in immune function between urban and rural birds observed in other studies. Moreover, it gives evidence that ALAN exposure affects nestling physiology, potentially causing long-term effects on physiology and behaviour, which ultimately can affect their fitness.}},
  author       = {{Ziegler, Ann-Kathrin and Watson, Hannah and Hegemann, Arne and Meitern, Richard and Canoine, Virginie and Nilsson, Jan-Åke and Isaksson, Caroline}},
  issn         = {{1477-9145}},
  language     = {{eng}},
  month        = {{05}},
  number       = {{10}},
  publisher    = {{The Company of Biologists Ltd}},
  series       = {{Journal of Experimental Biology}},
  title        = {{Exposure to artificial light at night alters innate immune response in wild great tit nestlings}},
  url          = {{http://dx.doi.org/10.1242/jeb.239350}},
  doi          = {{10.1242/jeb.239350}},
  volume       = {{224}},
  year         = {{2021}},
}