Dim light at night prior to adolescence increases adult anxiety-like behaviors

ABSTRACT

Dim light at night (dLAN) disrupts circadian organization and influences adult behavior. We examined early dLAN exposure on adult affective responses. Beginning 3 (juvenile) or 5 weeks (adolescent) of age, mice were maintained in standard light–dark cycles or exposed to nightly dLAN (5 lx) for 5 weeks, then anxiety-like and fear responses were assessed. Hypothalami were collected around the clock to assess core clock genes. Exposure to dLAN at either age increased anxiety-like responses in adults. Clock and Rev-ERB expression were altered by exposure to dLAN. In contrast to adults, dLAN exposure during early life increases anxiety and fear behavior.

KEYWORDS:

• Light at night
• anxiety
• fear conditioning
• circadian disruption
• early life

Acknowledgements

The authors thank Anupama Suresh, Tial KaiKai TinKai, Adam Weiss, Evan Thomas and Elise Lemanski for technical assistance.

Declaration of interest

This work was supported by the National Science Foundation grant IOS 11-18792 (RJN) and National Institutes of Health grant P30NS045758. YMC was supported by NIDCR T32DE014320.