Articles: function.
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The anterior cingulate cortex (ACC) plays an important role in higher brain functions including learning, memory, and persistent pain. Long-term potentiation of excitatory synaptic transmission has been observed in the ACC after digit amputation, which might contribute to plastic changes associated with the phantom pain. Here we report a long-lasting membrane potential depolarization in ACC neurons of adult rats after digit amputation in vivo. ⋯ The depolarization is activity-dependent, since peripheral application of lidocaine significantly reduced it. Furthermore, the depolarization was significantly reduced by a NMDA receptor antagonist MK-801. Our results provide direct in vivo electrophysiological evidence that ACC pyramidal cells undergo rapid and prolonged depolarization after digit amputation, and the amputation-induced depolarization in ACC neurons might be associated with the synaptic mechanisms for phantom pain.
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Cannabinoids have been known for their analgesic, anxiolytic, antiemetic and antispastic properties for many centuries. Since an endogenous cannabinoid system has been identified in the past two decades, cannabinoids have also become the focus of interest in western medicine. This review summarizes preclinical and clinical studies on the role of the endocannabinoid system and exogenous cannabinoids in anaesthesia and pain management. ⋯ In general, the results of the very few well-conducted clinical trials often diverge from the highly interesting and promising findings of preclinical studies. Taken together, the most recent preclinical and clinical data suggest that cannabinoids should be applied as low-dose co-analgesics to inhibit neuroplasticity and central sensitization rather than as analgesics in acute pain.
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Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). It is associated with local activation of microglia and astroglia, infiltration of activated macrophages and T cells, active degradation of myelin and damage to axons and neurons. The proposed role for CX3CL1 (fractalkine) in the control of microglia activation and leukocyte infiltration places this chemokine and its receptor CX3CR1 in a potentially strategic position to control key aspects in the pathological events that are associated with development of brain lesions in MS. In this study, we examine this hypothesis by analyzing the distribution, kinetics, regulation and cellular origin of CX3CL1 and CX3CR1 mRNA expression in the CNS of rats with an experimentally induced MS-like disease, myelin oligodendrocyte glycoprotein (MOG)-induced autoimmune encephalomyelitis (EAE). ⋯ Our data demonstrate constitutive and regulated expression of the chemokine CX3CL1 and its receptor CX3CR1 by neurons/astrocytes and microglia, respectively, within the normal and inflamed rat brain. Our findings propose a mechanism by which neurons and reactive astrocytes may control migration and function of the surrounding microglia. In addition, the accumulation of CX3CR1 expressing cells other than microglia within the inflammatory brain lesions indicate a possible role for CX3CL1 in controlling invasion of peripheral leucocytes to the brain.
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Postoperative epidural fibrosis may contribute to between 5% to 60% of the poor surgical outcomes following decompressive surgery. Correlations have been reported between epidural scarring and radicular pain, poor surgical outcomes, and a lack of any form of surgical treatment. The use of spinal endoscopic adhesiolysis in recent years in the management of chronic refractory low back and lower extremity pain has been described. ⋯ Spinal endoscopic adhesiolysis with targeted delivery of local anesthetic and steroid is an effective treatment in a significant number of patients with chronic low back and lower extremity pain without major adverse effects.
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Changes in epidemiology and advances in the treatment of coronary artery disease, hypertension and diabetes mellitus have increased the prevalence of heart failure in the general population, and also the number of patients with heart failure presenting for surgery. Particularly in the perioperative period, patients with chronic heart failure are faced with numerous triggers of acute decompensation that can partly be avoided or treated. Patients without preexisting myocardial contractile dysfunction may sustain severe perioperative complications, e.g. myocardial infarction, with subsequent acute heart failure as a consequence. Approaches for diagnosis and treatment in these situations may vary considerably. ⋯ The role of B-type natriuretic peptide testing in the perioperative period is confounded by several variables that limit its use in that setting. New developments in positive inotropic therapy are challenging older and potentially harmful treatment strategies.