Ramirez-Plascencia Oscar D, Saderi Nadia, Cárdenas Romero Skarleth, Flores Sandoval Omar, Báez-Ruiz Adrián, Martínez Barajas Herick, Salgado-Delgado Roberto
Facultad de Ciencias, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico.
Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.
Chronobiol Int. 2022 Mar;39(3):374-385. doi: 10.1080/07420528.2021.2002352. Epub 2021 Dec 14.
Temporal coordination of organisms according to the daytime allows a better performance of physiological processes. However, modern lifestyle habits, such as food intake during the rest phase, promote internal desynchronization and compromise homeostasis and health. The hypothalamic suprachiasmatic nucleus (SCN) synchronizes body physiology and behavior with the environmental light-dark cycle by transmitting time information to several integrative hypothalamic nuclei, such as the paraventricular nucleus (PVN), dorsomedial hypothalamic nucleus (DMH) and median preoptic area (MnPO). The SCN receives metabolic information mainly via Neuropeptide Y (NPY) inputs from the intergeniculate nucleus of the thalamus (IGL). Nowadays, there is no evidence of the response of the PVN, DMH and MnPO when the animals are subjected to internal desynchronization by restricting food access to the rest phase of the day. To explore this issue, we compared the circadian activity of the SCN, PVN, DMH and MnPO. In addition, we analyzed the daily activity of the satiety centers of the brainstem, the nucleus of the tractus solitarius (NTS) and area postrema (AP), which send metabolic information to the SCN, directly or via the thalamic intergeniculate leaflet (IGL). For that, male Wistar rats were assigned to three meal protocols: fed during the rest phase (Day Fed); fed during the active phase (Night Fed); free access to food (). After 21 d, the daily activity patterns of these nuclei were analyzed by c-Fos immunohistochemistry, as well as NPY immunohistochemistry, in the SCN. The results show that eating during the rest period produces a phase advance in the activity of the SCN, changes the daily activity pattern in the MnPO, NTS and AP and flattens the c-Fos rhythm in the PVN and DMH. Altogether, these results validate previous observations of circadian dysregulation that occurs within the central nervous system when meals are consumed during the rest phase, a behavior that is involved in the metabolic alterations described in the literature.
生物体根据白天进行时间协调可使生理过程表现得更好。然而，现代生活方式习惯，如在休息阶段进食，会导致内部不同步，并损害体内平衡和健康。下丘脑视交叉上核（SCN）通过将时间信息传递给几个下丘脑整合核，如室旁核（PVN）、下丘脑背内侧核（DMH）和视前正中区（MnPO），使身体生理和行为与环境明暗周期同步。SCN主要通过来自丘脑膝间核（IGL）的神经肽Y（NPY）输入接收代谢信息。目前，尚无证据表明当动物因在一天的休息阶段限制食物获取而出现内部不同步时，PVN、DMH和MnPO的反应情况。为探究此问题，我们比较了SCN、PVN、DMH和MnPO的昼夜活动。此外，我们分析了脑干饱食中枢、孤束核（NTS）和最后区（AP）的日常活动，它们直接或通过丘脑膝间小叶（IGL）向SCN发送代谢信息。为此，将雄性Wistar大鼠分为三种进食方案：在休息阶段进食（白天进食）；在活动阶段进食（夜间进食）；自由获取食物（自由进食）。21天后，通过c-Fos免疫组织化学以及SCN中的NPY免疫组织化学分析这些核的日常活动模式。结果表明，在休息期进食会使SCN的活动出现相位提前，改变MnPO、NTS和AP的日常活动模式，并使PVN和DMH中的c-Fos节律变平。总之，这些结果证实了先前的观察结果，即当在休息阶段进食时，中枢神经系统内会出现昼夜节律失调，这种行为与文献中描述的代谢改变有关。
