Articles: function.
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Isolectin B4-binding (IB4+) dorsal root ganglion (DRG) neurons are distinct from peptidergic DRG neurons in their terminal location in the spinal cord and respective contributions to various classes and modalities of nociception. In DRG neurons innervating the mouse colon (c-DRG neurons), the reported proportion of IB4+ population is inconsistent across studies, and little is known regarding their role in colorectal mechanonociception. To address these issues, in C57BL/6J mice, we quantified IB4+ binding after labeling c-DRG neurons with Fast Blue and examined functional consequences of ablating these neurons by IB4-conjugated saporin. ⋯ Intrathecal administration of IB4-conjugated saporin reduced the proportion of IB4+ c-DRG neurons to 37%, which was due to the loss of c-DRG neurons showing strong to medium IB4+ intensity; c-DRG neurons with weak IB4+ intensity were spared. However, this loss altered neither nociceptive behaviors to colorectal distension nor the relative proportions of stretch-sensitive colorectal afferent classes characterized by single-fiber recordings. These findings demonstrate that more than 1 half of viscerosensory L6 c-DRG neurons in C57BL/6J mouse are IB4+ and suggest, in contrast to the reported roles of IB4+/nonpeptidergic neurons in cutaneous mechanonociception, c-DRG neurons with strong-to-medium IB4+ intensity do not play a significant role in colorectal mechanonociception.
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Chronic musculoskeletal pain (CMP) conditions, like fibromyalgia, are associated with widespread pain and alterations in autonomic functions. Regular physical activity prevents the development of CMP and can reduce autonomic dysfunction. We tested if there were alterations in autonomic function of sedentary mice with CMP, and whether exercise reduced the autonomic dysfunction and pain induced by CMP. ⋯ There were no sex differences after induction of the CMP in any outcome measure. We further show that both 5 days and 8 weeks of physical activity prevent the development of autonomic dysfunction and decreases in withdrawal threshold induced by CMP. Thus, this study uniquely shows the development of autonomic dysfunction in animals with chronic muscle hyperalgesia, which can be prevented with as little as 5 days of physical activity, and suggest that physical activity may prevent the development of pain and autonomic dysfunction in people with CMP.
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Growing evidence demonstrates that a number of clinical disorders may be related to genetic defects in telomeres replication and extensions. Overall, these syndromes are referred to as telomeropathies or telomeres disorders or syndromes; they are increasingly being identified. In adulthood, idiopathic pulmonary fibrosis (IPF) is the most common symptom of telomeropathy. ⋯ In a cohort of patients addressed to lung transplantation, authors were able to demonstrate that subclinical bone marrow and liver abnormalities can be seen in patients with interstitial lung disease (ILD) and short telomeres, in some cases in the absence of clinically significant abnormalities in peripheral blood count and liver function tests. This observation sustains the rationale for further studies aimed to validate telomere length testing as a useful parameter as part of the evaluation for transplant candidacy. A deeper clarification of the complex link between IPF and short telomeres and telomeropathies is required for a new ILD classification, aimed to a fullpersonalized approach to the disease.