Tenemos tres tiempos que rigen nuestra cronobiología: el interno, que es el tiempo que nuestras células sienten como producto de habernos adaptado al ecosistema dónde vivimos; el externo, que es el de la luz solar y artificial; y el social, que es el de la hora a la que vamos a trabajar o comemos. Si están desincronizados, aparece un desequilibrio molecular y fisiológico denominado cronodisrupción
Definición de la «cronodisrupción»
Además del tiempo ambiental, que es el ciclo de luz y oscuridad natural, está el tiempo social: los hábitos horarios, como ir al trabajo o los contactos sociales, ayudan a sincronizar. El otro sincronizador es el tiempo metabólico, como los horarios de comida, que ayudan a controlar los relojes del tubo digestivo o del hígado
Tres factores para regular el reloj biológico:
su reloj biológico generaba ciclos de más de 24 horas.
Por eso hablamos del ritmo circadiana.
Zubek, J., Ziembowicz, K., Pokropski, M., Gwiaździński, P., Denkiewicz, M., & Boros, A. (2021). Rhythms of the day: How electronic media and daily routines influence mood during COVID-19 pandemic. PsyArXiv. https://doi.org/10.31234/osf.io/czg27
Bedder, R., Vaghi, M., Dolan, R., & Rutledge, R. (2020). Risk taking for potential losses but not gains increases with time of day. PsyArXiv. https://doi.org/10.31234/osf.io/3qdnx
Thyroxine treatment significantly lengthened TPX animals' cycles (average increase: 0.28 h) but did not affect intact rats' circadian rhythms.
This suggests that hypothyroidism shortens the circadian cycle, while hyperthyroidism does nothing. This is disappointing, and also counter to what I expected. However, it could still be consistent with my expectations if these effects are behaviorally mediated. That is to say, it could be greater stimulation that keeps them awake longer (which in turn effects the body clock). If that is the case, the alertness/dullness effects could be countered by depressants/stimulants, which would reveal the direct circadian impact.
Additionally, I'd like to know if T3 doses at wake time could provide any entrainment (or at night time). The half life of T3 is short enough that reveal phase effects. T4 only demonstrates net effects; like getting light exposure all day long, T4 may both delay and advance circadian phase.
Also note that all conditions have a distinct rightward tilt when graphed. That is to say, they have a body clock longer than 24 hours. It's quite plausible that the thyroid hormone could interact with zeitgebers.
a histone H3 lysine 9 methyltransferase (KMT1/Suv39h), RNA binding proteins, and the nucleosome remodeling and deacetylase (NuRD) corepressor
Essential to fully grok. Chart out. Link to other regulatory systems
When we eat at night, our blood glucose, HbA1c and insulin levels increase more and say elevated longer than when we eat earlier in the day, which can result in an elevated risk of type 2 diabetes over time.
The way this is worded is distracting because (so far as I understand) HbA1c doesn't fluctuate anywhere near as quickly as blood glucose and insulin.
Circadian rhythms of the peripheral clock genes are profoundly affected by fasting/feeding cycles.
rhythms in the uptake of the glucose analog 2-deoxyglucose (2-DG) precede the development of a functional TTFL
This could be interesting as well. Metabolic issues run through chronic illness. As do circadian dysfunctions, diabetes susceptibility,
An interactive network of bibliographic connections between some central proteins of the circadian clock, along with links to some major model organisms.
Beta blockers have long been associated with sleep disturbances such as difficulty falling asleep, staying asleep, and insomnia. They have been shown to reduce the production of melatonin via specific inhibition of beta-1 adrenergic receptors. Melatonin is a hormone secreted by the pineal gland in the brain, and helps in maintaining normal circadian rhythms.6,20-21 People with hypertension already have a lower melatonin production rate than those with normal blood pressure.22
The question becomes, then, do beta blockers impair sleep when exogenous melatonin is administered concurrently?