Neuroscience letters
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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
Reduced brain edema and infarct volume in aquaporin-4 deficient mice after transient focal cerebral ischemia.
Aquaporin-4 (AQP4) is a water channel expressed in astrocyte end-feet lining the blood-brain barrier. AQP4 deletion in mice is associated with improved outcomes in global cerebral ischemia produced by transient carotid artery occlusion, and focal cerebral ischemia produced by permanent middle cerebral artery occlusion (MCAO). ⋯ Diffusion-weighted magnetic resonance imaging showed greatest reduction in apparent diffusion coefficient around the occlusion site after reperfusion, with remarkably lesser reduction in AQP4(-/-) mice. The reduced infarct volume in AQP4(-/-) mice following transient MCAO supports the potential utility of therapeutic AQP4 inhibition in stroke.
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Neuroscience letters · Jan 2015
Hyperalgesia in an immobilized rat hindlimb: effect of treadmill exercise using non-immobilized limbs.
Cast immobilization of limbs causes hyperalgesia, which is a decline of the threshold of mechanical and thermal mechanical stimuli. The immobilization-induced hyperalgesia (IIH) can disturb rehabilitation and activities of daily living in patients with orthopedic disorders. However, it is unclear what therapeutic and preventive approaches can be used to alleviate IIH. ⋯ Beta-endorphin, which is one of the endogenous opioids, was selectively increased in the hypothalamus and midbrain periaqueductal gray of the Im+Ex group. Our data suggest that treadmill running using the non-immobilized limbs reduces the amount of hyperalgesia induced in the immobilized limb even if it is not freed. This ameliorating effect might be due to the descending pain modulatory system being activated by upregulation of beta-endorphin in the brain.
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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
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.