This study examines the feeding response induced by hypothalamic noradrenergic stimulation, in terms of the type and synaptic position of its mediating receptor. Tests with norepinephrine or the alpha 2 receptor agonist clonidine, injected into the area of the paraventricular nucleus (PVN), revealed a potent feeding response in satiated animals. This response by either agonist was blocked, in a dose-dependent fashion, by local injection of the alpha 2-noradrenergic antagonists, rauwolscine and yohimbine. It was also blocked by the general antagonist, phentolamine. In contrast, it was unaffected by hypothalamic injection of the alpha 1-noradrenergic antagonists, prazosin and corynanthine. These results indicate that feeding elicited by noradrenergic stimulation in the region of the PVN is mediated through alpha 2-type receptors. These alpha 2 receptors appear to be located postsynaptically, since the effectiveness of clonidine in eliciting eating was undisturbed by prior injection of the catecholamine synthesis inhibitor, alpha-methyl-p-tyrosine.
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http://dx.doi.org/10.1016/0014-2999(85)90578-3 | DOI Listing |
Neurobiol Stress
November 2024
Dept. of Psychiatry and Behavioral Neurosciences, School of Medicine, Wayne State University, Detroit, MI, USA.
In preclinical studies and our human laboratory, the α-noradrenergic autoreceptor antagonist yohimbine was found to promote drug-seeking behavior. This study evaluated effects of dose-combinations of yohimbine and the glucocorticoid receptor agonist hydrocortisone to model intensity-dependent effects of stimulating each neurochemical system, alone and together, on stress-reactivity and opioid-seeking. Twelve regular heroin-using participants diagnosed with opioid use disorder (OUD) were stabilized on sublingual buprenorphine (8-mg/day), then passed a hydromorphone 18-mg vs.
View Article and Find Full Text PDFPharmacol Biochem Behav
March 2024
Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil; NAP-USP-Neurobiology of Emotions Research Centre (NuPNE), Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil; Behavioural Neurosciences Institute (INeC), Avenida do Café, 2450, Ribeirão Preto 14220-030, São Paulo, Brazil.. Electronic address:
Gamma-aminobutyric acid (GABA) disinhibition in medial hypothalamus (MH) nuclei of rats elicits some defensive reactions that are considered panic attack-like behaviours. Recent evidence showed that the norepinephrine-mediated system modulates fear-related defensive behaviours organised by MH neurons at least in part via noradrenergic receptors recruitment on midbrain tegmentum. However, it is unknown whether noradrenergic receptors of the MH also modulate the panic attack-like reactions.
View Article and Find Full Text PDFFront Mol Neurosci
January 2023
Department of Medical Pharmacology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
SLITRK1 is a neuronal transmembrane protein with neurite development-and synaptic formation-controlling abilities. Several rare variants of SLITRK1 have been identified and implicated in the pathogenesis of Tourette's syndrome, trichotillomania, and obsessive-compulsive disorder, which can be collectively referred to as obsessive-compulsive-spectrum disorders. Recent studies have reported a possible association between bipolar disorder and schizophrenia, including a revertant of modern human-specific amino acid residues.
View Article and Find Full Text PDFFront Behav Neurosci
October 2019
School of Psychology, University of Birmingham, Birmingham, United Kingdom.
Brain Res
December 2019
Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil; NAP-USP-Neurobiology of Emotions Research Centre (NuPNE), Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil; Behavioural Neurosciences Institute (INeC), Avenida do Café, 2450, Ribeirão Preto 14220-030, São Paulo, Brazil. Electronic address:
Dorsal raphe nucleus (DRN) neurons are reciprocally connected to the locus coeruleus (LC) and send neural pathways to the medial hypothalamus (MH). The aim of this work was to investigate whether the blockade of α-, α- or β-noradrenergic receptors in the DRN or the inactivation of noradrenergic neurons in the LC modify defensive behaviours organised by MH neurons. For this purpose, Wistar male rats received microinjections of WB4101, RX821002, propranolol (α- α- and β-noradrenergic receptor antagonists, respectively) or physiological saline in the DRN, followed 10 min later by MH GABA receptor blockade.
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