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NMDA receptors have been widely reported to be involved in the regulation of synaptic plasticity through effects on long-term potentiation (LTP) and long-term depression (LTD). LTP and LTD have been implicated in learning and memory processes. Besides synaptic plasticity, it is known that the phenomenon of gamma oscillations is critical in cognitive functions. Synaptic plasticity has been widely studied, however it is still not clear, to what degree synaptic plasticity regulates the oscillations of neuronal networks. Two NMDA receptor antagonists, ketamine and memantine, have been shown to regulate LTP and LTD, to promote cognitive functions, and have even been reported to bring therapeutic effects in major depression and Alzheimer's disease respectively. These compounds allow us to investigate the putative interrelationship between network oscillations and synaptic plasticity and to learn more about the mechanisms of their therapeutic effects. In the present study, we have identified that ketamine and memantine could inhibit LTD, without impairing LTP in the CA1 region of mouse hippocampus, which may underlie the mechanism of these drugs' therapeutic effects. Our results suggest that NMDA-induced LTD caused a marked loss in the gamma power, and pretreatment with 10 μM ketamine prevented the oscillatory loss via its inhibitory effect on LTD. Our study provides a new understanding of the role of NMDA receptors on hippocampal plasticity and oscillations.

NIRS was used to predict the amino acid profile of freeze-dried pork samples. Samples (150; Longissimus thoracis et lumborum) of pork were used for analysis. After freeze drying, samples were analyzed using HPLC to find out the amino acid content. Samples were scanned and partial least squares (PLS) regression methods were used to predict the amino acid. The determination coefficient obtained by full cross-validated (80 as a sample for calibration set, 25 samples as a validation set) PLS models indicated that the NIR original spectra had an excellent ability to predict the contents of alanine, proline and methionine. Prediction of glutamic acid and glycine using standard normalized variate (SNV) pretreatment of spectral modeling was accurate. Similarly, prediction of arginine, tyrosine, valine, isoleucine, leucine, phenylalanine and lysine were accurate using SNV or multiplicative scattering correction (MSC) pre-processing spectra modeling. It was not possible to predict aspartic acid, serine, threonine, cystine, and histidine. These results indicated that the NIRS can be used for prediction of selected amino acids in the freeze dried pork. [ABSTRACT FROM AUTHOR]

Vascular anomalies are among the most common congenital and neonatal dysmorphogenesis, which are separated into hemangiomas and vascular malformations. They can occur in various areas throughout the body, with 60% being located in the head and neck. The true mechanism of pathogenesis of vascular anomalies is still unclear. Various treatment methods have been reported, and there are still controversies over the selection of different treatment modalities. Based on the clinical and basic research and current literature, the Chinese Division of Oral and Maxillofacial Vascular Anomalies formulated a treatment guideline for hemangiomas and vascular malformations of the head and neck, which will be modified and updated periodically based on new medical evidence and research. © 2009 Wiley Periodicals, Inc. Head Neck, 2010 [ABSTRACT FROM AUTHOR]

PURPOSE: The purpose of this study is to introduce the preliminary application of rapid prototyping (RP) for temporomandibular joint (TMJ) surgery. METHODS: 11 consecutive patients (13 joints) seeking for TMJ replacement were included in this study. All patients had previously undergone 3-dimensional computed tomography (CT) scannings (0.625mm slice thickness) of the craniofacial skeleton. The data from CT scan with DICOM format were input into an interactive Simplant CMF software (Materialise Medical, Leuven, Belgium). Preoperative planning included segmentation and osteotomies. The movements of the jaw hones was simulated using the Simplant CMF. The affected mandible was reconstructed, based on the contralateral side. Then the titanium plate was shaped on the reconstructed model before operation. The bone graft was transplanted by the shaped titanium plate during the operation to reconstruct the TMJ. 24 patients receiving traditional surgery were used as control. The operation time of the two group were analyzed with SPSS 13.0 software package for Student's t test. The data of CT scan of the experimental group before and after operation were compared by paired t test. RESULTS: All the incisions were healed primarily without any complications. All patients were satisfied with the operation, due to their symmetrical face and good occlusion. The postoperative MRI confirmed the position of transplanted costchondral cartilage in the glenoid fossa. Group t test showed that the operation time was longer in control group (7.09h) than that in RP group (5.67h). Three parameters (condyle-incisor, CI; condyle-mental foramen, CM; condyle-angle, CA) from the postoperative CT scan were analyzed by paired t test, and there was no significant difference between the two sides. CONCLUSION: Rapid prototyping technology provides an advanced method for TMJ reconstruction, which can make the TMJ reconstruction more accurate and symmetrical, improve the mandibular function and consequently enhance the reconstructive effect. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality (Grant No.08DZ2271100), Shanghai Leading Academic Discipline Project (Grant No.S30206), Research Fund of Shanghai Municipal Bureau of Health (Grant No.2008 160), Research Fund of Ph.D. Programs of Shanghai Jiao Tong University School of Medicine (Grant No.BXJ0926), and Research Fund of Medicine and Engineering of Shanghai Jiao Tong University (Grant No.YG2009MS 42). [ABSTRACT FROM AUTHOR]

Aim: N-methyl- D-aspartate receptors (NMDAR) are heteromeric complexes primarily assembled from NR1 and NR2 subunits. In normal conditions, NR2 sub-units assemble into homodimers in the endoplasmic reticulum (ER). These homodimers remain in the ER until they coassemble with NR1 dimers and are trafficked to the cell surface. However, it still remains unclear whether functional homomeric NMDAR exist in physiological or pathological conditions. Methods: We transfected GFP-NR2A alone into HEK293 cells, treated the cells with PKC activator 12-myristate-13 acetate (PMA), and then detected surface NR2A sub-units with a live cell immunostaining method. We also used a series of NR2A mutants with a partial deletion of its C-terminus to identify the regions that are involved in the PMA-mediated surface expression of NR2A subunits. Results: NR2A subunits were expressed on the cell membrane after incubation with PMA (200 nmol/L, 30 min), although no functional NMDA channels were detected after PMA-induced membrane trafficking. Immunostaining with an ER marker also revealed that NR2A subunits were exported from the ER after PMA treatment. Furthermore, the deletion of amino acids between 1149-1347 or 1354-1464 of NR2A inhibited PMA-induced surface expression of NR2A subunits. Conclusion: First, our data suggests that PMA treatment can induce the surface expression of homomeric NR2A subunits. Furthermore, this process is probably mediated by the NR2A C-terminal region between positions 1149 and 1464. [ABSTRACT FROM AUTHOR]

Interactions between neurons and glial cells in the brain may serve important functions in the development, maintenance, and plasticity of neural circuits. Fast neuron-glia synaptic transmission has been found between hippocampal neurons and NG2 cells, a distinct population of macroglia-like cells widely distributed in the brain. We report that these neuron-glia synapses undergo activity-dependent modifications analogous to long-term potentiation (LTP) at excitatory synapses, a hallmark of neuronal plasticity. However, unlike the induction of LTP at many neuron-neuron synapses, both induction and expression of LTP at neuron-NG2 synapses involve Ca2--permeable AMPA receptors on NG2 cells. [ABSTRACT FROM AUTHOR]

The corpus callosum is the largest commissural system in the mammalian brain, but the mechanisms underlying its development are not well understood. Here we report that neuronal activity is necessary for the normal development and maintenance of callosal projections in the mouse somatosensory cortex. We labeled a subpopulation of layer II/III callosal neurons via in utero electroporation and traced their axons in the contralateral cortex at different postnatal stages. Callosal axons displayed region- and layer-specific projection patterns within the first 2 weeks postnatally. Prenatal suppression of neuronal excitation was achieved via electroporation-induced overexpression of the inward rectifying potassium channel Kir2.1 in layer II/III cortical neurons. This resulted in abnormal callosal projections with many axons extending beyond layers II-III to terminate in layer I. Others failed to terminate at the border between the primary and secondary somatosensory cortices. Blocking synaptic transmission via expression of the tetanus toxin light chain (TeNT-LC) in these axons produced a more pronounced reduction in the projections to the border region, and the eventual disappearance of callosal projections over the entire somatosensory cortex. When Kir2.1 and TeNT-LC were coexpressed, callosal axon targeting exhibited a more severe phenotype that appeared to represent the addition of the effects produced by individual expression of Kir2.1 and TeNT-LC. These results underscore the importance of activity in regulating the developing neural connections and suggest that neuronal and synaptic activities are involved in regulating different aspects of the development of callosal projection. [ABSTRACT FROM AUTHOR]