The orexinergic neurons of the lateral hypothalamus (Orx) are essential for regulating sleep-wake dynamics, and their loss causes narcolepsy, a disorder characterized by severe instability of sleep and wake states. However, the mechanisms through which Orx stabilize sleep and wake are not well understood. In this work, an explanation of the stabilizing effects of Orx is presented using a quanti...

OBJECTIVE The hypothalamic neuropeptide orexin influences (feeding) behavior as well as energy metabolism. Administration of exogenous orexin-A into the brain has been shown to increase both food intake and blood glucose levels. In the present study, we investigated the role of endogenous hypothalamic orexin release in glucose homeostasis in rats. RESEARCH DESIGN AND METHODS We investigated t...

NORMAL CARDIOVASCULAR CONTROL is accomplished by a close interplay of homeostatic feedback mechanisms, such as the baroreceptor and chemoreceptor reflexes, and adaptive feedforward mechanisms that allow the organism to adapt to environmental changes and behavioral responses, such as exercise, hunting, fighting, or escape from predators. A hallmark of the adaptive mechanisms is an involvement of...

A large variety of behaviors that are essential for animal survival depend on the perception and processing of surrounding smells present in the natural environment. In particular, food-search behavior, which is conditioned by hunger, is directly driven by the perception of odors associated with food, and feeding status modulates olfactory sensitivity. The orexinergic hypothalamic peptide orexi...

The orexinergic system comprises the neuropeptides, orexin A and B, which are exclusively produced in the posterior, lateral and paraventricular parts of the hypothalamus (1–3). Orexins act via G-protein-coupled OX1 and OX2 receptors on projections to the prefrontal cortex, thalamus and other subcortical areas to promote arousal (4) and exert modulating effects on nociceptive neurotransmission,...

Orexinergic/hypocretinergic (Ox) neurotransmission plays an important role in regulating sleep, as well as in anxiety and depression, for which the serotonergic (5-HT) system is also involved in. However, little is known regarding the direct and indirect interactions between 5-HT in the dorsal raphe nucleus (DRN) and Ox neurons in the lateral hypothalamus (LHA). In this study, we report the add...