Brain research
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Levodopa is the main medication used for the treatment of Parkinson's disease. However, dyskinesia and wearing-off appear after the administration of high-dose levodopa for a long period. To combat the dyskinesia and wearing-off, levodopa is used together with a dopamine (DA) receptor agonist, and the amount of levodopa is decreased. ⋯ The striatal DA concentrations in the model rat brains were significantly increased by using levodopa/DDCI together with entacapone. Motor function was recovered by raising the striatum DA density in the model rats. Thus, COMT inhibitors are useful for decreasing the amount of levodopa administered to Parkinson's disease patients.
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Intracerebral hemorrhage (ICH) is a devastating stroke with no clinically proven treatment. Deferoxamine (DFX), an iron chelator, is a promising therapy that lessens edema, mitigates peri-hematoma cell death, and improves behavioral recovery after whole-blood-induced ICH in rodents. In this model, blood is directly injected into the brain, usually into the striatum. ⋯ Therefore, in contrast to studies using the whole-blood model, DFX treatment did not improve outcome in the collagenase model. Our findings, when compared to others, suggest that there are critical differences between these ICH models. Perhaps, the current clinical work with DFX will help identify the more clinically predictive model for future neuroprotection studies.
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Empathy is an important component of human relationships, yet the neural mechanisms that facilitate empathy are unclear. The broad construct of empathy incorporates both cognitive and affective components. Cognitive empathy includes mentalizing skills such as perspective-taking. ⋯ Specifically, neural activity in the IFG, SRC, and STS were related to cognitive empathy. Activity in the precentral gyrus was related to affective empathy. The findings suggest that both simulation and mentalizing networks contribute to multiple components of empathy.
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Protein 4.1 (band 4.1 or 4.1R) was originally identified as an abundant protein of the human erythrocyte, in which it stabilizes the spectrin/actin cytoskeleton. Subsequently, several new family members, 4.1N, 4.1G and 4.1B, have been identified, which are expressed in many cell types, in particular at cell-cell junctions. ⋯ Additionally, we found that 4.1B is ablated in the hair cells of both myosin XV and whirlin mutant mice at all stages in hair cell development. These results suggest that 4.1 family members play important roles in the development and maintenance of the inner ear hair cells, and that 4.1B may be a member of the myosin XV-whirlin complex that is important for stereocilia maturation.
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To test the hypothesis that the cellular mechanism whereby chronic deep brain stimulation of the subthalamic nucleus (STN-DBS) induces the improvement of motor deficits lasting after stimulation in the hemiparkinsonian (hemi-PD) rat involves the NMDA receptor-dependent processes in neurons receiving afferents from the STN, we examined whether the NMDA receptor antagonist prevents the alleviating after-effect of repeated STN-DBS on motor deficits in hemi-PD. The cylinder test was performed before and after repeated STN-DBS over 3 days in hemi-PD that received a unilateral injection of 6-OHDA into the medial forebrain bundle 3 weeks prior to STN-DBS experiments. ⋯ Both MK-801 (0.1 mg/kg) and CPP (0.5 mg/kg) completely prevented the improvement of the akinetic motor deficit after repeated STN-DBS. These results support the hypothesis that activation of the NMDA receptor and subsequent cellular processes in neurons receiving the afferents from the STN may involve in the mechanism underlying the alleviating after-effect of chronic STN-DBS on the akinetic motor deficit in hemi-PD.