34 research outputs found
Adropin acts in brain to inhibit water drinking: potential interaction with the orphan G protein-coupled receptor, GPR19
In this paper, we are interested in the problem of smoothing parameter
selection in nonparametric curve estimation under dependent errors. We focus on
kernel estimation and the case when the errors form a general stationary
sequence of martingale difference random variables where neither linearity
assumption nor "all moments are finite" are required.We compare the behaviors
of the smoothing bandwidths obtained by minimizing either the unknown average
squared error, the theoretical mean average squared error, a Mallows-type
criterion adapted to the dependent case and the family of criteria known as
generalized cross validation (GCV) extensions of the Mallows' criterion. We
prove that these three minimizers and those based on the GCV family are
first-order equivalent in probability. We give also a normal asymptotic
behavior of the gap between the minimizer of the average square error and that
of the Mallows-type criterion. This is extended to the GCV family.Finally, we
apply our theoretical results to a specific case of martingale difference
sequence, namely the Auto-Regressive Conditional Heteroscedastic (ARCH(1))
process.A Monte-carlo simulation study, for this regression model with ARCH(1)
process, is conducted.Comment: Bernoulli journal, In pres
The anorexigenic and hypertensive effects of nesfatin-1 are reversed by pretreatment with an oxytocin receptor antagonist
Nesfatin-1 is an 82-amino acid protein encoded by the nucleobindin2 gene. When injected intracerebroventricularly, nesfatin-1, via a melanocortin ¾ receptor-dependent mechanism, potently decreased both food and water intakes and elevated mean arterial pressure in a dose-related manner. Because nesfatin-1 colocalized with oxytocin in hypothalamus and because nesfatin-1 had direct depolarizing effects on oxytocin-producing neurons in hypothalamic slice preparations, we hypothesized that the actions of nesfatin-1 required the presence of functional oxytocin receptors. We, therefore, pretreated conscious, unrestrained male rats with the oxytocin receptor antagonist, ornithine vasotocin (OVT), before treatment with nesfatin-1. We found that pretreatment with OVT reversed the effects of nesfatin-1 on both food and water intake and on mean arterial pressure, indicating that the central oxytocin system is a downstream mediator of these actions of nesfatin-1. Additionally, we found that OVT reversed the anorexigenic effect of α-melanocyte-stimulating hormone (α-MSH), suggesting that the central oxytocin system is downstream of the central melanocortin system. Taken together, these data suggest that nesfatin-1 acts through a serial neuronal circuit, in which nesfatin-1 activates the central melanocortin system, which, in turn, acts through the central oxytocin system, leading to an inhibition of food and water intake and an increase in mean arterial pressure