Cortical functioning within the default mode network (DMN) and salience network (SN) is altered in chronic pain patients. The mechanisms underlying these alterations are unknown, but a novel unexamined source is cross-network communication. Aberrant functional connectivity (FC) between the DMN and SN, whose activity is normally anticorrelated, reflects disease severity in many brain disorders. Further, stronger FC between the posterior cingulate cortex (PCC) and anterior insula has been reported in chronic pain, pointing to abnormal DMN-SN interactions. Here, we tested the hypothesis that cross-network FC between the DMN and SN is abnormal in chronic pain, and is related to pain and associated symptoms. We used resting state fMRI to examine FC within and between the DMN and SN in 20 patients with chronic pain due to ankylosing spondylitis and 20 healthy controls. A whole-network analysis revealed that compared to healthy controls, patients exhibited less anticorrelated FC between the SN and DMN, and the degree of cross-network abnormality tracked pain and disease-related symptoms. This suggests that cross-network FC is a metric of functional brain abnormality in chronic pain. In a complementary seed-based analysis, the PCC was strongly connected with the SN and weakly connected with the DMN in chronic pain compared to healthy controls, suggesting that the PCC acts as a hub for altered network interaction. Sensorimotor cortex cross-network FC correlated with measures of physical function, suggesting that physical functioning also impacts brain network interaction in chronic pain. Our study implicates altered communication between brain networks as a key factor underlying chronic pain.

Over the last ten years, Oosterhof and Todorov's valence-dominance model has emerged as the most prominent account of how people evaluate faces on social dimensions. In this model, two dimensions (valence and dominance) underpin social judgments of faces. Because this model has primarily been developed and tested in Western regions, it is unclear whether these findings apply to other regions. We addressed this question by replicating Oosterhof and Todorov's methodology across 11 world regions, 41 countries, and 11,570 participants. When we used Oosterhof and Todorov's original analysis strategy, the valence-dominance model generalized across regions. When we used an alternative methodology to allow for correlated dimensions we observed much less generalization. Collectively, these results suggest that, while the valence-dominance model generalizes very well across regions when dimensions are forced to be orthogonal, regional differences are revealed when we use different extraction methods, correlate and rotate the dimension reduction solution.

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Objective. To determine whether there is a neuropathic component in ankylosing spondylitis (AS) back pain and to delineate gray matter brain abnormalities associated with AS.Methods. Seventeen patients with back pain secondary to AS who were not receiving biologic agents and 17 age-and sex-matched healthy controls consented to participate in the study and were assessed using the painDETECT instrument (scores of <12 indicating low probability of neuropathic pain) and the McGill Pain Questionnaire. Mechanical and thermal thresholds were determined in all subjects, and brain gray matter was assessed by 3T magnetic resonance imaging.Results. Eleven of the 17 AS patients had pain-DETECT scores of >12. The patients had decreased mechanical and cold sensitivity on the dorsum of their feet but did not have altered pain thresholds. Compared to controls, the AS patients exhibited cortical thinning in the primary somatosensory, insular, anterior cingulate, and anterior mid-cingulate cortices and the supplemental motor area, and increased gray matter volume in the thalamus and putamen. Scores on the painDETECT in AS patients were correlated with decreased gray matter in the primary somatosensory cortex and with increased gray matter in the motor cortex, anterior cingulate cortex, prefrontal cortex, thalamus, and striatum.Conclusion. The present findings indicate that neuropathic pain occurs in AS. Furthermore, abnormal brain gray matter and neural correlates of neuropathic pain are concordant with the clinical picture of AS, which includes sensorimotor and mood deficits as well as neuropathic pain symptoms. These results suggest that back pain in AS is a mixed pain condition that includes a neuropathic pain component.

High-content, image-based screens enable the identification of compounds that induce cellular responses similar to those of known drugs but through different chemical structures or targets. A central challenge in designing phenotypic screens is choosing suitable imaging biomarkers. Here we present a method for systematically identifying optimal reporter cell lines for annotating compound libraries (ORACLs), whose phenotypic profiles most accurately classify a training set of known drugs. We generate a library of fluorescently tagged reporter cell lines, and let analytical criteria determine which among them—the ORACL—best classifies compounds into multiple, diverse drug classes. We demonstrate that an ORACL can functionally annotate large compound libraries across diverse drug classes in a single-pass screen and confirm high prediction accuracy via orthogonal, secondary validation assays. Our approach will increase the efficiency, scale and accuracy of phenotypic screens by maximizing their discriminatory power.

Previously, we described an APC-adenovirus (APC-Ad) FasL cell gene therapy method which could be used to deplete autoreactive T cells in vivo. FasL was toxic, however, and controlled regulation of FasL was not achieved. Here we describe an improved approach to delivering TNF-related apoptosis-inducing ligand (TRAIL) in vivo in which collagen II-induced (CII-induced) arthritis-susceptible (CIA-susceptible) DBA/1j mice were treated with CII-pulsed DCs that had been transfected with a novel Ad system. The Ad was engineered to exhibit inducible TRAIL under the control of the doxycycline-inducible (DOX-inducible) tetracycline response element (TRE). Four groups of mice were treated with CII-DCAdTRAIL+DOX, CII-DC-AdTRAIL (no DOX), CII-DC-AdGFP+DOX, or DC-AdTRAIL+DOX (no CII), beginning 2 weeks after priming with CII in CFA. The incidence of arthritis and infiltration of T cells in the joint was significantly decreased in CII-DC-AdTRAIL+DOX-treated mice. The in vitro splenic T cell proliferative response and induction of IFN-γ to bovine CII stimulation were also significantly reduced in mice treated with CII-DC-AdTRAIL+DOX. AdTRAIL+DOX was not toxic to DCs or mice but could induce activated T cells to undergo apoptosis in the spleen. Our results suggest that CII-DCAdTRAIL+DOX cell gene therapy is a safe and effective method for inhibiting the development of CIA.

Copper may play an important role in the brain in aging and neurodegenerative diseases. We compare the active Cu uptake, Cu-containing enzyme levels, and total Cu distribution in the brains of young and aging mice. (67)Cu was administered intravenously to 2, 7-9, and 14 month old mice. Active uptake of (67)Cu in the brain was measured at 24 h by digital phosphor autoradiography. Cerebral superoxide dismutase-1 (SOD-1) and cytochrome-C oxidase subunit-1 (CCO-1) levels were analyzed by immunohistochemistry. The total Cu distribution in brain section was determined by imaging laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). In aging mice, active (67)Cu uptake and SOD-1 levels were significantly decreased in the brain, whereas blood (67)Cu and CCO-1 levels were similar for all mice, irrespective of age. Paradoxically, global Cu cerebral content was increased in aged mice, suggesting that regulation of active Cu uptake by the brain may be linked to total Cu levels in an attempt to maintain Cu homeostasis. However, focal areas of both decreased Cu uptake and Cu content were noted in the striatum and ventral cortex in aging mice. These focal areas of Cu deficit correspond to the regions of greatest reduction in SOD-1 in the aged mice. In aging, dysregulated Cu homeostasis may result in decreased SOD-1 levels, which may contribute to oxidative vulnerability of the aging brain. This study illustrates the importance of a multi-modality approach in studying the biodistribution and homeostasis of Cu in the brain.

BackgroundThe aim of this study was to compare primary sensory neurons in controls and in an animal neuropathic pain model in order to understand which types of neurons undergo changes associated with peripheral neuropathy. On the basis of intracellular recordings in vivo from somata, L4 sensory dorsal root ganglion neurons were categorized according to action potential configuration, conduction velocity, and receptive field properties to mechanical stimuli.MethodsIntracellular recordings were made from functionally identified dorsal root ganglion neurons in vivo in the Mosconi and Kruger animal model of peripheral neuropathic pain.ResultsIn this peripheral neuropathy model, a specific population of Aβ-fiber low threshold mechanoreceptor neurons, which respond normally to innocuous mechanical stimuli, exhibited differences in action potential configuration and conduction velocity when compared with control animals. No abnormal conduction velocity, action potential shapes, or tactile sensitivity of C-fiber neurons were encountered.ConclusionThis study provides evidence for defining a potential role of Aβ-fiber low threshold mechanoreceptor neurons that might contribute to peripheral neuropathic pain.