Lenka Polidarová, Martin Sládek, Zuzana Novosadová, Alena Sumová. Aging does not compromise in vitro oscillation of the suprachiasmatic nuclei but makes it more vulnerable to constant light. Chronobiology International 34 (2016).

To investigate the consequences of aging on the ability of the suprachiasmatic nuclei of the hypothalamus (SCN) to generate rhythm, we used different lighting regimes to entrain or disrupt circadian rhythmicity in adult and aged mPer2^Luc mice and studied the effects on behavior and circadian oscillations of explanted SCNs in vitro. The results demonstrate that although age worsened the SCN output rhythm, the SCN molecular core clock mechanism itself was relatively resilient to aging in these same animals.

Fig. A: Locomotor activity of adult and aged mPer2^Luc mice kept on constant light regime for 7-9 months. B: Endogenous period of PER2 circadian luminescence of SCN explants from adult and aged mice. C: Circadian oscillations of PER2 luminescence from SCN explants of adult and aged mice kept on constant light rescued in vitro by periodic medium exchange.