OBJECTIVES Intracerebroventricular injection of orexin-A (hypocretin-1) antagonist has been shown to inhibit stress-induced analgesia. However the locations of central sites that may mediate these effects have not been totally demonstrated. This study was performed to investigate the role of rostral ventromedial medulla (RVM) orexin receptor 1 in stress-induced analgesia (SIA). MATERIALS AND ...

Anatomical and physiological studies conducted in the 1960s identified the periaqueductal gray (PAG) and its descending projections to the rostral ventromedial medulla (RVM) and spinal cord dorsal horn, as a primary anatomical pathway mediating opioid-based analgesia. Since these initial studies, the PAG-RVM-spinal cord pathway has been characterized anatomically and physiologically in a wide r...

The present study was aimed to compare in detail the distribution within the rostral ventromedial medulla of Methionin-Enkephalin-immunoreactive neurons with efferent projections to the facial or trigeminal motor nuclei, using a double immunostaining technique in colchicine-treated cats. Following cholera toxin B subunit injections in the facial or trigeminal motor nuclei, we found that respect...

Pain is more than merely nociception and response, but rather it encompasses emotional, behavioral and cognitive components that make up the pain experience. With the recent advances in imaging techniques, we now understand that nociceptive inputs can result in the activation of complex interactions among central sites, including cortical regions that are active in cognitive, emotional and rewa...

Opioid receptor modulation of GABAergic and serotonergic spinally-projecting neurons of 1 the rostral ventromedial medulla in mice 2 3 Abbreviated title: Opioid modulation of GABAergic neurons in the RVM 4 5 Authors: 6 Nigel P. Pedersen (1,2), Christopher W. Vaughan (2), MacDonald J. Christie (1) 7 8 Affiliations: 9 (1) Brain & Mind Research Institute, University of Sydney, NSW 2006, Australia,...

Substance P Enhances Excitatory Synaptic Transmission on Spinally 1 Projecting Neurons in the Rostral Ventromedial Medulla After Inflammatory 2 Injury 3 Liang Zhang and Donna L. Hammond 4 Departments of Anesthesia and Pharmacology 5 The University of Iowa 6 Iowa City, IA 52242 U.S.A. 7 Abstract: 249 words Introduction: 697 words Discussion: 2142 words 8 Tables: 0 Figures: 8 9 Running Title: Inf...

In placebo hypoalgesia research, the strength of treatment expectations and experiences are key components. However, the reliability or precision of expectations had been mostly ignored although being a likely source for interindividual differences. In the present study, we adopted a Bayesian framework, naturally combining expectation magnitudes and precisions. This postulates that expectations...

Pain thresholds are, in part, set as a function of emotional and internal states by descending modulation of nociceptive transmission in the spinal cord. Neurons of the rostral ventromedial medulla (RVM) are thought to critically contribute to this process; however, the neural circuits and synaptic mechanisms by which distinct populations of RVM neurons facilitate or diminish pain remain elusiv...