Orexin A activates locus coeruleus cell firing and increases arousal in the rat.
نویسندگان
چکیده
The localization of orexin neuropeptides in the lateral hypothalamus has focused interest on their role in ingestion. The orexigenic neurones in the lateral hypothalamus, however, project widely in the brain, and thus the physiological role of orexins is likely to be complex. Here we describe an investigation of the action of orexin A in modulating the arousal state of rats by using a combination of tissue localization and electrophysiological and behavioral techniques. We show that the brain region receiving the densest innervation from orexinergic nerves is the locus coeruleus, a key modulator of attentional state, where application of orexin A increases cell firing of intrinsic noradrenergic neurones. Orexin A increases arousal and locomotor activity and modulates neuroendocrine function. The data suggest that orexin A plays an important role in orchestrating the sleep-wake cycle.
منابع مشابه
Role of Orexin-A receptors within the Locus Coeruleus in the antinociception induced by microinjection of carbachol into the lateral hypothalamus
Introduction: Previous studies have shown that stimulation of lateral hypothalamus (LH) produces antinociception. Orexin-A (OXA) receptor is strongly expressed in the nucleus locus coeruleus (LC) and orexinergic fibers densely project from LH to LC. In this study, we assessed the role of LC and its OXA receptors in antinociceptive response induced by LH chemical stimulation in the rat. Meth...
متن کاملMicroinjection of orexin-A into the locus coeruleus area induces morphine withdrawal-like behaviors in morphine dependent rats
Introduction: It has been shown that orexin peptides have a role in opioid withdrawal behaviors. Orexin-expressing neurons that are present in the hypothalamic nuclei send dense projections to the Locus Coeruleus (LC). Withdrawal syndrome is temporally associated with hyperactivity of LC neurons. However, LC neurons do not show withdrawalinduced hyperactivity in the brain slices from morphin...
متن کاملHypocretin-1 causes G protein activation and increases ACh release in rat pons.
The effects of the arousal-promoting peptide hypocretin on brain stem G protein activation and ACh release were examined using 16 adult Sprague-Dawley rats. In vitro[35S]GTPgammaS autoradiography was used to test the hypothesis that hypocretin-1-stimulated G protein activation is concentration-dependent and blocked by the hypocretin receptor antagonist SB-334867. Activated G proteins were quant...
متن کاملHalothane-induced hypnosis is not accompanied by inactivation of orexinergic output in rodents.
BACKGROUND One underexploited property of anesthetics is their ability to probe neuronal regulation of arousal. At appropriate doses, anesthetics reversibly obtund conscious perception. However, individual anesthetic agents may accomplish this by altering the function of distinct neuronal populations. Previously the authors showed that isoflurane and sevoflurane inhibit orexinergic neurons, del...
متن کاملOrganization of hypocretin/orexin efferents to locus coeruleus and basal forebrain arousal-related structures.
Hypocretin/orexin neurons give rise to an extensive projection system, portions of which innervate multiple regions associated with the regulation of behavioral state. These regions include the locus coeruleus, medial septal area, medial preoptic area, and substantia innominata. Evidence indicates that hypocretin modulates behavioral state via actions within each of these terminal fields. To un...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 96 19 شماره
صفحات -
تاریخ انتشار 1999