Neuroscience
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Regeneration in the adult mammalian spinal cord is limited due to intrinsic properties of mature neurons and a hostile environment, mainly provided by central nervous system myelin and reactive astrocytes. Recent results indicate that propriospinal connections are a promising target for intervention to improve functional recovery. To study this functional regeneration in vitro we developed a model consisting of two organotypic spinal cord slices placed adjacently on multi-electrode arrays. ⋯ This reduction was not accompanied by an inability for axons to cross the lesion site. We show that functional regeneration in these old cultures can be improved by increasing the intracellular cAMP level with Rolipram or by placing a young slice next to an old one directly after the lesion. We conclude that co-cultures of two spinal cord slices are an appropriate model to study functional regeneration of intraspinal connections.
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Guillain-Barré syndrome (GBS) is an acute, post-infectious, immune-mediated, demyelinating disease of peripheral nerves and nerve roots. Experimental autoimmune neuritis (EAN) is an animal model of GBS. Chrysin, which is a naturally occurring flavonoid, exhibits various biological activities. ⋯ In the sciatic nerves, the expression of inducible nitric oxide synthase, cyclooxygenase-2 and nuclear factor kappa B was reduced. Furthermore, chrysin inhibited the splenic mononuclear cell secretion of interleukin-1β, interleukin-2, interleukin-6, inteleukin-12, interferon γ and tumor necrosis factor α, and elevated the level of inteleukin-4. In summary, our data demonstrate that chrysin is a potentially useful agent for the treatment of EAN with its anti-inflammatory and neuroprotective effects.
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Both neuregulin 1 (NRG1) and its receptor ErbB4 are susceptibility genes for schizophrenia. Reduced synchronization of evoked oscillations in several cortical regions, especially in the prefrontal cortex, is associated with the core symptoms of schizophrenia. Recent studies have reported that NRG1 may affect the hippocampal oscillations. ⋯ Moreover, the NRG1-enhanced synchrony of interneurons was through their mutually-inhibitory synapses but not electrical coupling. Furthermore, kainate-induced gamma oscillations in vivo were enhanced by NRG1 and did not change in Dlx5/6-ErbB4(-/-) mice in which the ErbB4 receptors were specifically knocked out in interneurons of the frontal brain. Overall, our findings suggested that NRG1/ErbB4 signaling plays an important role in the synchronized oscillations of the whole network in the prefrontal cortex that are impaired in schizophrenia.
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Comparative Study
Motor execution and motor imagery: a comparison of functional connectivity patterns based on graph theory.
Motor execution and imagery (ME and MI), as the basic abilities of human beings, have been considered to be effective strategies in motor skill learning and motor abilities rehabilitation. Neuroimaging studies have revealed several critical regions from functional activation for ME as well as MI. ⋯ Our results showed that using BC, the key node for the ME task mainly focused on the supplementary motor area, while the key node for the MI task mainly located in the right premotor area. These results characterized the connectivity patterns of ME and MI and may provide new insights into the neural mechanism underlying motor execution and imagination of movements.
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In the present study we investigated the effects of anodal transcranial direct current stimulation over the auditory cortex (AC) on the perception of rapidly changing acoustic cues. For this purpose, in 15 native German speakers the left or right AC was separately stimulated while participants performed a between-channel gap detection task. ⋯ Our data indicate a left hemispheric dominance for the processing of rapid temporal cues in auditory non-speech sounds. Moreover, we demonstrate the ability of non-invasive brain stimulation to change human temporal information processing in the auditory domain.