Depressive-like behavior is elevated among offspring of parents exposed to dim light at night prior to mating.
Rates of major depressive disorder (MDD) have steadily increased over the past 50 years. Many factors have been implicated in the etiology of depressive disorders and environmental influences are being increasingly recognized. The increase in depression rates has coincided with increased artificial nighttime lighting. Exposure to light at night (LAN) has been associated with increased depressive-like behavior in rodents and decreased mood in humans. However, relatively little is known on the multigenerational effects of dLAN on affect. In this study, we exposed adult male and female Siberian hamsters (Phodopus sungorus) to either DARK (0lx) or dim LAN (5lx) for 9 weeks, then paired animals in a full factorial design; all animals were thereafter housed in dark nights. Offspring were gestated and reared in dark nights, then tested in adulthood for depressive-like behaviors and hippocampal expression of glucocorticoid (GR) and melatonin (MT1) receptor expression. Maternal exposure to dLAN decreased sucrose preference, time to first float bout in the Porsolt swim test, and GR expression in the hippocampus. Paternal exposure to dLAN increased time spent floating, and increased hippocampal GR expression. Overall, our results suggest that chronic exposure of parents to light at night has multigenerational effects on offspring depressive-like behavior. If these results pertain to humans, then our data suggest that LAN may contribute to the rapidly rising rates of major depressive disorder in industrialized and developing countries.
['Cissé|Yasmine M|YM|', 'Russart|Kathryn L G|KLG|', 'Nelson|Randy J|RJ|']
D000818:Animals D001522:Behavior, Animal D002940:Circadian Rhythm D006224:Cricetinae D003863:Depression D003865:Depressive Disorder, Major D005260:Female D005938:Glucocorticoids D006624:Hippocampus D008029:Lighting D008297:Male D018811:Maternal Exposure D018812:Paternal Exposure D017111:Phodopus D017440:Photoperiod D011247:Pregnancy D011297:Prenatal Exposure Delayed Effects D044122:Receptor, Melatonin, MT1 D012098:Reproduction
Light at night Depression Circadian disruption Light pollution Transgenerational