Neuroscience
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Colivelin is a neuroprotective humanin family peptide with potent long-term capacity against Aβ deposition, neuronal apoptosis, and synaptic plasticity deficits in neurodegenerative disease. We seek to investigate whether this effect of Colivelin also govern ischemic brain injury, and potential mechanism underlying the Colivelin-mediated action on ischemic neurons. We adopted 60 min induction of transient focal cerebral ischemia and reperfusion in mice. ⋯ Moreover, Colivelin activated STAT3 signaling, which may partially contribute to its beneficial effect against neuronal death and axon growth. In conclusion, Colivelin induce anti-apoptotic genes up-regulation, and activate JAK/STAT3 signaling after ischemic stroke, which may contribute to its effects of rescuing ischemic neuronal death and axonal remodeling. This study may justify further works to examine Colivelin as a single or adjunct therapy in ischemic stroke.
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The great majority of neurons in the superficial dorsal horn of the spinal cord are excitatory interneurons, and these are required for the normal perception of pain and itch. We have previously identified 5 largely non-overlapping populations among these cells, based on the expression of four different neuropeptides (cholecystokinin, neurotensin, neurokinin B and substance P) and of green fluorescent protein driven by the promoter for gastrin-releasing peptide (GRP) in a transgenic mouse line. Another peptide (neuropeptide FF, NPFF) has been identified among the excitatory neurons, and here we have used an antibody against the NPFF precursor (pro-NPFF) and a probe that recognises Npff mRNA to identify and characterise these cells. ⋯ By examining phosphorylation of extracellular signal-regulated kinases, we show that the NPFF cells can respond to different types of noxious and pruritic stimulus. Ablation of somatostatin-expressing dorsal horn neurons has been shown to result in a dramatic reduction in mechanical pain sensitivity, while somatostatin released from these neurons is thought to contribute to itch. Since the great majority of the NPFF cells co-expressed somatostatin, these cells may play a role in the perception of pain and itch.
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Given their anti-inflammatory properties, cannabinoids have been shown to be neuroprotective agents and to reduce excitotoxicity, through the activation of the Cannabinoid receptor type 1 (CB1r). These properties have led to CB1r being proposed as pharmacological targets for the treatment of various neurodegenerative diseases. Amyloid-β 25-35 (Aβ25-35) induces the expression of inducible nitric oxide synthase (iNOS) and increases nitric oxide (NO●) levels. ⋯ Moreover, ACEA plus Aβ(25-35) prevented both the increase in iNOS protein and NO● levels and the reactive gliosis induced by Aβ(25-35). Importantly, neurodegeneration was significantly reduced by the administration of ACEA plus Aβ(25-35) in the CA1 subfield of the hippocampus. The data obtained in the present research suggest that the acute early activation of CB1r is crucial for neuroprotection.
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Multiple sclerosis (MS) is a demyelination disease that causes gradual damage to neurons. Despite the necessity of appropriate treatments at each disease stage to prevent the worsening of the damage, it is still difficult to cure MS. In this study, metabolomics and lipidomics studies were performed with time-course plasma samples (early, peak, chronic phase for MS) to elucidate the mechanism during MS progression after induction of experimental autoimmune encephalomyelitis (EAE), which is the animal model for multiple sclerosis (MS). ⋯ In particular, 26 metabolites showed significant differences at specific stages. The metabolite level of the plasma was significantly altered in response to the EAE pathogenesis, and these changes were related to inflammation status at each disease stage. This study can provide crucial information for reducing damage by differentiating treatment strategies according to disease progression.
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Nerve damage leads to the development of disabling neuropathic pain in susceptible individuals, where patients present with pain as well as co-morbid affective behavioural disturbances, such as anhedonia, decreased motivation and depression. In this study we aimed to characterise changes in neuroinflammation in the medial prefrontal cortex (mPFC) and hippocampus (HP) in a rat model of neuropathic pain (NP) and behavioural changes. 53 rats underwent sciatic nerve chronic constriction injury (CCI) and were characterised as either, No effect, Acute effect or Lasting effect on the basis of changes in exploration behaviour in a radial-arm maze. Microglial and astrocyte morphology, as well as IL-1β, IL-6, IL-10, MCP-1, p38 MAPK and BDNF expression was quantified throughout the mPFC and HP using protein multiplex assays and immunofluorescence. ⋯ This includes increased expression of IL-1β, IL-6 and MCP-1, increased phospho-p38 MAPK expression in neurons and microglia, and a shift to a reactive microglial morphology in the caudal PL and IL, ventral CA1 and DG. Therefore, neuroinflammation in the mPFC and ventral HP may influence individual differences in radial-arm maze behaviour following CCI. Our data provide further evidence that individual differences in neuroimmune activation in the interconnected ventral HP-mPFC circuitry may play a role in the divergent behavioural trajectories following nerve injury, with neuroinflammation being coincident with affective behavioural changes in susceptible individuals.