Neuroscience letters
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Neuroscience letters · Jan 2015
Rosuvastatin attenuated the existing morphine tolerance in rats with L5 spinal nerve transection through inhibiting activation of astrocytes and phosphorylation of ERK42/44.
Recent studies suggested that statins have anti-inflammatory effects beyond their lipid-lowering properties. In the present study, we sought to investigate whether rosuvastatin could alleviate morphine tolerance by attenuating the glia mediated neuroinflammation in the spinal cord. Using a rat model of L5 spinal nerve transection, on day 8 after surgery morphine (10 mg/kg) was injected subcutaneously twice daily for consecutive 10 days. ⋯ Rosuvastatin administration for 5 days could restore morphine antinociceptive effect significantly. Additionally, the activation of astrocytes, the phosphorylation of extracellular signal-regulated kinase 42/44 (ERK(42/44)) and the expressions of TNFα and IL-1β were inhibited significantly by rosuvastatin. Our data suggested that rosuvastatin was a promising choice to treat neuropathic pain in combination with morphine.
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Neuroscience letters · Jan 2015
Intra-articular administration of an antibody against CSF-1 receptor reduces pain-related behaviors and inflammation in CFA-induced knee arthritis.
Several studies have shown that blockade of colony stimulating factor-1 (CSF-1) or its receptor (CSF-1R) inhibits disease progression in rodent models of rheumatoid arthritis (RA); however, the role of the CSF-1/CSF-1R pathway in RA-induced pain and functional deficits has not been studied. Thus, we examined the effect of chronic intra-articular administration of a monoclonal anti-CSF-1R antibody (AFS98) on spontaneous pain, knee edema and functional disabilities in mice with arthritis. Unilateral arthritis was produced by multiple injections of complete Freund's adjuvant (CFA) into the right knee joint of adult male ICR mice. ⋯ Intra-articular treatment with anti-CSF-1R antibody significantly increased horizontal exploratory activity and vertical rearing as well as reduced spontaneous flinching behavior and knee edema as compared to CFA-induced arthritis mice treated with PBS. Treatment with this antibody neither significantly affect mouse body weight nor the number of peripheral leukocytes. These results suggest that blockade of CSF-1R at the initial injury site (joint) could represent a therapeutic alternative for improving the functional disabilities and attenuating pain and inflammation in patients with RA.
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Neuroscience letters · Jan 2015
What is the optimal anodal electrode position for inducing corticomotor excitability changes in transcranial direct current stimulation?
Transcranial direct current stimulation (tDCS) non-invasively modulates brain function by inducing neuronal excitability. The conventional hot spot for inducing the highest current density in the hand motor area may not be the optimal site for effective stimulation. In this study, we investigated the influence of the center position of the anodal electrode on changes in motor cortical excitability. ⋯ Motor cortical excitability as measured by MEP amplitude increased after both real stimulation conditions, but not after sham stimulation. Stimulation using the simulation-derived anodal electrode position, which was found to be posterior to the MEP hot spot for all subjects, induced higher motor cortical excitability. Individual positioning of the anodal electrode, based on the consideration of anatomical differences between subjects, appears to be important for maximizing the effects of tDCS.
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Neuroscience letters · Jan 2015
Preliminary evidence for the interaction of the oxytocin receptor gene (oxtr) and face processing in differentiating prenatal smoking patterns.
Prenatal smoking cessation has been described as an empathic action "for the baby," but this has not been empirically demonstrated. We capitalized on a genetically-characterized extant dataset with outstanding measurement of prenatal smoking patterns and maternal face processing data (as an indicator of empathy) to test this hypothesis, and explore how empathy and smoking patterns may be moderated by a genetic substrate of empathy, the oxytocin receptor gene (OXTR). Participants were 143 Caucasian women from the East Boston family study with repeated prospective reports of smoking level, adjusted based on repeated cotinine bioassays. ⋯ Of these, 21% quit during pregnancy; 56% reduced smoking, and 22% smoked persistently at the same level. A significant interaction between face processing and OXTR variants previously associated with increased sensitivity to social context, rs53576GG and rs2254298A, was found (β = -.181; p = .015); greater ability to identify distress in others was associated with lower levels of smoking during pregnancy for rs53576(GG)/rs2254298(A) individuals (p = .013), but not for other genotypes (p = .892). Testing this "empathy hypothesis of prenatal smoking cessation" in larger studies designed to examine this question can elucidate whether interventions to enhance empathy can improve prenatal smoking cessation rates.
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Neuroscience letters · Jan 2015
Suppression of network activity in dorsal horn by gabapentin permeation of TRPV1 channels: implications for drug access to cytoplasmic targets.
The effectiveness of gabapentin (GBP) in the treatment of neuropathic pain depends on access to the α2δ-1 accessory subunit of voltage-gated Ca(2+) channels. Access may be limited by its rate of entry via the neuronal system L-neutral amino acid transporter. The open pore of capsaicin-activated TRPV1 channel admits organic molecules such as local anesthetics and we calculated that GBP entry via this route would be 500× more rapid than via the transporter. ⋯ Experiments with an inhibitor of the neutral amino acid transporter, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH 300 μM), showed the actions of GBP seen in the presence of capsaicin were independent of its entry by this route. Capsaicin potentiation of GBP depression of dorsal horn activity may therefore reflect drug permeation of TRPV1 channels. Agonist activation of TRP channels may provide a means for improving drug access to cytoplasmic targets in selective neuronal populations defined on the basis of type of TRP channel expressed.