Premium
Recurring circadian disruption alters circadian clock sensitivity to resetting
Author(s) -
Leise Tanya L.,
Goldberg Ariella,
Michael John,
Montoya Grace,
Solow Sabrina,
Molyneux Penny,
Vetrivelan Ramalingam,
Harrington Mary E.
Publication year - 2020
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.14179
Subject(s) - circadian rhythm , suprachiasmatic nucleus , light effects on circadian rhythm , biology , neuroscience , circadian clock , rhythm , phase response curve , endocrinology , medicine
A single phase advance of the light:dark ( LD ) cycle can temporarily disrupt synchrony of neural circadian rhythms within the suprachiasmatic nucleus ( SCN ) and between the SCN and peripheral tissues. Compounding this, modern life can involve repeated disruptive light conditions. To model chronic disruption to the circadian system, we exposed male mice to more than a month of a 20‐hr light cycle ( LD 10:10), which mice typically cannot entrain to. Control animals were housed under LD 12:12. We measured locomotor activity and body temperature rhythms in vivo, and rhythms of PER 2:: LUC bioluminescence in SCN and peripheral tissues ex vivo. Unexpectedly, we discovered strong effects of the time of dissection on circadian phase of PER 2:: LUC bioluminescent rhythms, which varied across tissues. White adipose tissue was strongly reset by dissection, while thymus phase appeared independent of dissection timing. Prior light exposure impacted the SCN , resulting in strong resetting of SCN phase by dissection for mice housed under LD 10:10, and weak phase shifts by time of dissection in SCN from control LD 12:12 mice. These findings suggest that exposure to circadian disruption may desynchronize SCN neurons, increasing network sensitivity to perturbations. We propose that tissues with a weakened circadian network, such as the SCN under disruptive light conditions, or with little to no coupling, for example, some peripheral tissues, will show increased resetting effects. In particular, exposure to light at inconsistent circadian times on a recurring weekly basis disrupts circadian rhythms and alters sensitivity of the SCN neural pacemaker to dissection time.