TY - JOUR
T1 - Disrupted Circadian Control of Hormonal Rhythms and Anticipatory Thirst by Dim Light at Night
AU - Okuliarova, Monika
AU - Dzirbikova, Zuzana
AU - Rumanova, Valentina Sophia
AU - Foppen, Ewout
AU - Kalsbeek, Andries
AU - Zeman, Michal
N1 - Funding Information: The study was supported by the Slovak Research and Development Agency (grant APVV-17-0178) and the Scientific Grant Agency of the Ministry of Education of the Slovak Republic (grant VEGA 1/0492/19) to Michal Zeman. Publisher Copyright: © 2022 S. Karger AG, Basel. Copyright: All rights reserved.
PY - 2022/10/1
Y1 - 2022/10/1
N2 - AIMS: Our study addresses underlying mechanisms of disruption of the circadian timing system by low-intensity artificial light at night (ALAN), which is a growing global problem, associated with serious health consequences. METHODS: Rats were exposed to low-intensity (∼2 lx) ALAN for 2 weeks. Using in situ hybridization, we assessed 24-h profiles of clock and clock-controlled genes in the suprachiasmatic nuclei (SCN) and other hypothalamic regions, which receive input from the master clock. Moreover, we measured the daily rhythms of hormones within the main neuroendocrine axes as well as the detailed daily pattern of feeding and drinking behavior in metabolic cages. RESULTS: ALAN strongly suppressed the molecular clockwork in the SCN, as indicated by the suppressed rhythmicity in the clock (Per1, Per2, and Nr1d1) and clock output (arginine vasopressin) genes. ALAN disturbed rhythmic Per1 expression in the paraventricular and dorsomedial hypothalamic nuclei, which convey the circadian signals from the master clock to endocrine and behavioral rhythms. Disruption of hormonal output pathways was manifested by the suppressed and phase-advanced corticosterone rhythm and lost daily variations in plasma melatonin, testosterone, and vasopressin. Importantly, ALAN altered the daily profile in food and water intake and eliminated the clock-controlled surge of drinking 2 h prior to the onset of the rest period, indicating disturbed circadian control of anticipatory thirst and fluid balance during sleep. CONCLUSION: Our findings highlight compromised time-keeping function of the central clock and multiple circadian outputs, through which ALAN disturbs the temporal organization of physiology and behavior.
AB - AIMS: Our study addresses underlying mechanisms of disruption of the circadian timing system by low-intensity artificial light at night (ALAN), which is a growing global problem, associated with serious health consequences. METHODS: Rats were exposed to low-intensity (∼2 lx) ALAN for 2 weeks. Using in situ hybridization, we assessed 24-h profiles of clock and clock-controlled genes in the suprachiasmatic nuclei (SCN) and other hypothalamic regions, which receive input from the master clock. Moreover, we measured the daily rhythms of hormones within the main neuroendocrine axes as well as the detailed daily pattern of feeding and drinking behavior in metabolic cages. RESULTS: ALAN strongly suppressed the molecular clockwork in the SCN, as indicated by the suppressed rhythmicity in the clock (Per1, Per2, and Nr1d1) and clock output (arginine vasopressin) genes. ALAN disturbed rhythmic Per1 expression in the paraventricular and dorsomedial hypothalamic nuclei, which convey the circadian signals from the master clock to endocrine and behavioral rhythms. Disruption of hormonal output pathways was manifested by the suppressed and phase-advanced corticosterone rhythm and lost daily variations in plasma melatonin, testosterone, and vasopressin. Importantly, ALAN altered the daily profile in food and water intake and eliminated the clock-controlled surge of drinking 2 h prior to the onset of the rest period, indicating disturbed circadian control of anticipatory thirst and fluid balance during sleep. CONCLUSION: Our findings highlight compromised time-keeping function of the central clock and multiple circadian outputs, through which ALAN disturbs the temporal organization of physiology and behavior.
KW - Anticipatory thirst
KW - Artificial light at night
KW - Chronodisruption
KW - Circadian rhythms
KW - Hormones
KW - Hypothalamus
UR - http://www.scopus.com/inward/record.url?scp=85138017555&partnerID=8YFLogxK
U2 - https://doi.org/10.1159/000524235
DO - https://doi.org/10.1159/000524235
M3 - Article
C2 - 35316813
SN - 0028-3835
VL - 112
SP - 1116
EP - 1128
JO - Neuroendocrinology
JF - Neuroendocrinology
IS - 11
ER -