225 research outputs found
Circuit dissection of the role of somatostatin in itch and pain
Stimuli that elicit itch are detected by sensory neurons that innervate the skin. This information is processed by the spinal cord; however, the way in which this occurs is still poorly understood. Here we investigated the neuronal pathways for itch neurotransmission, particularly the contribution of the neuropeptide somatostatin. We find that in the periphery, somatostatin is exclusively expressed in Nppb+ neurons, and we demonstrate that Nppb+somatostatin+ cells function as pruriceptors. Employing chemogenetics, pharmacology and cell-specific ablation methods, we demonstrate that somatostatin potentiates itch by inhibiting inhibitory dynorphin neurons, which results in disinhibition of GRPR+ neurons. Furthermore, elimination of somatostatin from primary afferents and/or from spinal interneurons demonstrates differential involvement of the peptide released from these sources in itch and pain. Our results define the neural circuit underlying somatostatin-induced itch and characterize a contrasting antinociceptive role for the peptide
Enteric Neurospheres Are Not Specific to Neural Crest Cultures: Implications for Neural Stem Cell Therapies
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited
Uplifting manhood to wonderful heights? News coverage of the human costs of military conflict from world war I to Gulf war Two
Domestic political support is an important factor constraining the use of American military power around the world. Although the dynamics of war support are thought to reflect a cost-benefit calculus, with costs represented by numbers of friendly war deaths, no previous study has examined how information about friendly, enemy, and civilian casualties is routinely presented to domestic audiences. This paper establishes a baseline measure of historical casualty reporting by examining New York Times coverage of five major wars that occurred over the past century. Despite important between-war differences in the scale of casualties, the use of conscription, the type of warfare, and the use of censorship, the frequency of casualty reporting and the framing of casualty reports has remained fairly consistent over the past 100 years. Casualties are rarely mentioned in American war coverage. When casualties are reported, it is often in ways that minimize or downplay the human costs of war
A Greater Means to the Greater Good: Ethical Guidelines to Meet Social Movement Organization Advocacy Challenges
Existing public relations ethics literature often proves inadequate when applied to social movement campaigns, considering the special communication challenges activists face as marginalized moral visionaries in a commercial public sphere. The communications of counter-hegemonic movements is distinct enough from corporate, nonprofit, and governmental organizations to warrant its own ethical guidelines. The unique communication guidelines most relevant to social movement organizations include promoting asymmetrical advocacy to a greater extent than is required for more powerful organizations and building flexibility into the TARES principles to privilege social responsibility over respect for audience values in activist campaigns serving as ideological critique
BCL11B Regulates Epithelial Proliferation and Asymmetric Development of the Mouse Mandibular Incisor
Mouse incisors grow continuously throughout life with enamel deposition uniquely on the outer, or labial, side of the tooth. Asymmetric enamel deposition is due to the presence of enamel-secreting ameloblasts exclusively within the labial epithelium of the incisor. We have previously shown that mice lacking the transcription factor BCL11B/CTIP2 (BCL11B hereafter) exhibit severely disrupted ameloblast formation in the developing incisor. We now report that BCL11B is a key factor controlling epithelial proliferation and overall developmental asymmetry of the mouse incisor: BCL11B is necessary for proliferation of the labial epithelium and development of the epithelial stem cell niche, which gives rise to ameloblasts; conversely, BCL11B suppresses epithelial proliferation, and development of stem cells and ameloblasts on the inner, or lingual, side of the incisor. This bidirectional action of BCL11B in the incisor epithelia appears responsible for the asymmetry of ameloblast localization in developing incisor. Underlying these spatio-specific functions of BCL11B in incisor development is the regulation of a large gene network comprised of genes encoding several members of the FGF and TGFβ superfamilies, Sprouty proteins, and Sonic hedgehog. Our data integrate BCL11B into these pathways during incisor development and reveal the molecular mechanisms that underlie phenotypes of both Bcl11b−/− and Sprouty mutant mice
Wnt5a Regulates Midbrain Dopaminergic Axon Growth and Guidance
During development, precise temporal and spatial gradients are responsible for
guiding axons to their appropriate targets. Within the developing ventral
midbrain (VM) the cues that guide dopaminergic (DA) axons to their forebrain
targets remain to be fully elucidated. Wnts are morphogens that have been
identified as axon guidance molecules. Several Wnts are expressed in the VM
where they regulate the birth of DA neurons. Here, we describe that a precise
temporo-spatial expression of Wnt5a accompanies the development of nigrostriatal
projections by VM DA neurons. In mice at E11.5, Wnt5a is
expressed in the VM where it was found to promote DA neurite and axonal growth
in VM primary cultures. By E14.5, when DA axons are approaching their striatal
target, Wnt5a causes DA neurite retraction in primary cultures. Co-culture of VM
explants with Wnt5a-overexpressing cell aggregates revealed that Wnt5a is
capable of repelling DA neurites. Antagonism experiments revealed that the
effects of Wnt5a are mediated by the Frizzled receptors and by the small GTPase,
Rac1 (a component of the non-canonical Wnt planar cell polarity pathway).
Moreover, the effects were specific as they could be blocked by Wnt5a antibody,
sFRPs and RYK-Fc. The importance of Wnt5a in DA axon morphogenesis was further
verified in Wnt5a−/− mice, where
fasciculation of the medial forebrain bundle (MFB) as well as the density of DA
neurites in the MFB and striatal terminals were disrupted. Thus, our results
identify a novel role of Wnt5a in DA axon growth and guidance
Spin Glass and Antiferromagnetic Behaviour in a Diluted fcc Antiferromagnet
We report on a Monte Carlo study of a diluted Ising antiferromagnet on a fcc
lattice. This is a typical model example of a highly frustrated
antiferromagnet, and we ask, whether sufficient random dilution of spins does
produce a spin glass phase. Our data strongly indicate the existence of a spin
glass transition for spin--concentration : We find a divergent spin
glass susceptibility and a divergent spin glass correlation length, whereas the
antiferromagnetic correlation length saturates in this regime. Furthermore, we
find a first order phase transition to an antiferromagnet for ,
which becomes continuous in the range . Finite size scaling is
employed to obtain critical exponents. We compare our results with experimental
systems as diluted frustrated antiferromagnets as .Comment: 29 pages (revtex) and 10 figures uuencoded and Z-compresse
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