CNS Imaging Characteristics in Fibromyalgia Patients With and Without Peripheral Nerve Involvement

We tested the hypothesis that reduced skin innervation in fibromyalgia syndrome is associated with specific CNS changes. This prospective case-control study included 43 women diagnosed with fibromyalgia syndrome and 40 healthy controls. We further compared the fibromyalgia subgroups with reduced (n=21) and normal (n=22) skin innervation. Brains were analysed for cortical thickness, for white matter integrity, and for functional connectivity. Compared to controls, cortical thickness was decreased in the left pars opercularis in the fibromyalgia group as a whole, and decreased in the left superior frontal and left rostral middle frontal cortex in the fibromyalgia subgroup with reduced skin innervation. Diffusion tensor imaging revealed a significant increase in fractional anisotropy in the corona radiata, the corpus callosum, cingulum and fornix in patients with fibromyalgia compared to healthy controls. Using resting-state fMRI, the fibromyalgia group as a whole showed functional hypoconnectivity between the right midfrontal gyrus and the posterior cerebellum and the right crus cerebellum, respectively. The subgroup with reduced skin innervation showed hyperconnectivity between the right cuneal cortex and the anterior parahippocampal gyrus, between the left thalamus and the lateral parietal region in the default mode network and hypoconnectivity between the left frontal lobe and the right cerebellum crus 1. Our results suggest that the subgroup of fibromyalgia patients with pronounced pathology in the peripheral nervous system shows distinctly altered morphology, structural and functional connectivity also at the level of the brain. We propose considering these subgroups when conducting clinical trials.

Transparent Touch: Insights From Model Systems on Epidermal Control of Somatosensory Innervation

Somatosensory neurons (SSNs) densely innervate our largest organ, the skin, and shape our experience of the world, mediating responses to sensory stimuli including touch, pressure, and temperature. Historically, epidermal contributions to somatosensation, including roles in shaping innervation patterns and responses to sensory stimuli, have been understudied. However, recent work demonstrates that epidermal signals dictate patterns of SSN skin innervation through a variety of mechanisms including targeting afferents to the epidermis, providing instructive cues for branching morphogenesis, growth control and structural stability of neurites, and facilitating neurite-neurite interactions. Here, we focus onstudies conducted in worms (Caenorhabditis elegans), fruit flies (Drosophila melanogaster), and zebrafish (Danio rerio): prominent model systems in which anatomical and genetic analyses have defined fundamental principles by which epidermal cells govern SSN development.

Treatment of Diabetic Neuropathy with A Novel PAR1-Targeting Molecule

Diabetic peripheral neuropathy (DPN) is a disabling common complication of diabetes mellitus (DM). Thrombin, a coagulation factor, is increased in DM and affects nerve function via its G-protein coupled protease activated receptor 1 (PAR1). Methods: A novel PAR1 modulator (PARIN5) was designed based on the thrombin PAR1 recognition site. Coagulation, motor and sensory function and small fiber loss were evaluated by employing the murine streptozotocin diabetes model. Results: PARIN5 showed a safe coagulation profile and showed no significant effect on weight or glucose levels. Diabetic mice spent shorter time on the rotarod (p < 0.001), and had hypoalgesia (p < 0.05), slow conduction velocity (p < 0.0001) and reduced skin innervation (p < 0.0001). Treatment with PARIN5 significantly improved rotarod performance (p < 0.05), normalized hypoalgesia (p < 0.05), attenuated slowing of nerve conduction velocity (p < 0.05) and improved skin innervation (p <0.0001). Conclusion: PARIN5 is a novel pharmacological approach for prevention of DPN development, via PAR1 pathway modulation.

Dermo-optical perception of the visible range different wavelengths electromagnetic radiation by the palms skin of visually

Background. There is no single point of view which would explain the exact mechanisms of dermo-optical perception and nonspecific stimuli brain processing features at the moment, but to understand this perception peculiarities it is important to study the different skin receptors response to different colors. Objectives. The work aim is to determine the visible range different wavelengths electromagnetic radiation influence on the palms skin different types somatosensory receptors activity and nerve fibers involved in the skin innervation. Materials and methods. The experiments involved 12 visually impaired children (at their request and with their parents permission). The various somatosensory receptors condition measurement located on the palms, as well as the skin innervation of visually impaired children who participated in the dermo-optical perception training, was performed using the device "KSD" by recording and computer analysis of the electromagnetic oscillations emitted by the organism. Results. An experimental study of changes in the various somatosensory receptors activity located on the palms, as well as the visually impaired children skin innervation under the visible range different wavelengths electromagnetic radiation action was performed. It was found that under the light action, depending on the specific wavelengths, the studied receptors and nerve fibers are activated or suppressed. An increase in the thermal sensitivity activity (Ruffini's body) under the electromagnetic radiation influence on the palms skin in the wave range from 380-700 nm (in the entire visible light spectral range). The greatest activation was observed in «warm» (red, orange) and green colors. On white, black and «cold» colors (blue, blue) the Ruffini's bodies activation was less than on «warm» colors. Conclusions. The obtained experimental results indicate the palms skin various somatosensory receptors ability to adapt to the some information perception with a non-specific stimulus - the visible range electromagnetic radiation. It was found that the palms skin dermo-optical perception is due not only to temperature sensitivity (provided by thermoreceptors), but also to other types of receptors: baroreceptors (Pacinian corpuscles), tactile receptors (Meissner's corpuscles), mechanoreceptors (Golgi receptors).