TY - JOUR
T1 - Effects of feeding time on daily rhythms of neuropeptide and clock gene expression in the rat hypothalamus
AU - Wang, Dawei
AU - Opperhuizen, Anne-Loes
AU - Reznick, Jane
AU - Turner, Nigel
AU - Su, Yan
AU - Cooney, Gregory J
AU - Kalsbeek, A.
N1 - Copyright © 2017. Published by Elsevier B.V.
PY - 2017
Y1 - 2017
N2 - Shiftworkers are exposed to several adverse health conditions, one being eating at night. Food consumption at an unnatural time-of-day is thought to be one of the main factors responsible for the increased risk of developing metabolic diseases, such as obesity and diabetes mellitus. The underlying mechanism is considered to include disruption of the circadian organization of physiology, leading to disruption of metabolism. When food is consumed at night, the hypothalamus, a brain region central to homeostasis, receives contradicting input from the central clock and the systemic circulation. This study investigated how timing of feeding affects hypothalamic function by studying, in different hypothalamic nuclei, expression of clock genes and key neuropeptide genes involved in energy metabolism, including orexin, melanin-concentrating hormone (MCH) and neuropeptide Y. Animals with food available ad libitum showed diurnal variation in the expression of clock genes Per1 and Per2 in the perifornical area and arcuate nucleus. Clock gene rhythms were lost in both nuclei when food was restricted to the light (i.e., sleep) period. Neuropeptide genes did not display significant daily variation in either feeding groups, except for orexin-receptor 1 in ad libitum animals. Analysis of genes involved in glutamatergic and GABAergic signaling did not reveal diurnal variation in expression, nor effects of feeding time. In conclusion, feeding at the 'wrong' time-of-day not only induces desynchronization between brain and body clocks but also within the hypothalamus, which may contribute further to the underlying pathology of metabolic dysregulation.
AB - Shiftworkers are exposed to several adverse health conditions, one being eating at night. Food consumption at an unnatural time-of-day is thought to be one of the main factors responsible for the increased risk of developing metabolic diseases, such as obesity and diabetes mellitus. The underlying mechanism is considered to include disruption of the circadian organization of physiology, leading to disruption of metabolism. When food is consumed at night, the hypothalamus, a brain region central to homeostasis, receives contradicting input from the central clock and the systemic circulation. This study investigated how timing of feeding affects hypothalamic function by studying, in different hypothalamic nuclei, expression of clock genes and key neuropeptide genes involved in energy metabolism, including orexin, melanin-concentrating hormone (MCH) and neuropeptide Y. Animals with food available ad libitum showed diurnal variation in the expression of clock genes Per1 and Per2 in the perifornical area and arcuate nucleus. Clock gene rhythms were lost in both nuclei when food was restricted to the light (i.e., sleep) period. Neuropeptide genes did not display significant daily variation in either feeding groups, except for orexin-receptor 1 in ad libitum animals. Analysis of genes involved in glutamatergic and GABAergic signaling did not reveal diurnal variation in expression, nor effects of feeding time. In conclusion, feeding at the 'wrong' time-of-day not only induces desynchronization between brain and body clocks but also within the hypothalamus, which may contribute further to the underlying pathology of metabolic dysregulation.
KW - Journal Article
U2 - 10.1016/j.brainres.2017.07.006
DO - 10.1016/j.brainres.2017.07.006
M3 - Article
C2 - 28709906
SN - 0006-8993
VL - 1671
SP - 93
EP - 101
JO - Brain Research
JF - Brain Research
ER -