Activation of the excitatory neurotransmitter N-methyl-d-aspartate (NMDA) and stretching both increase Ca(2+) influx in osteoblastic cells. We postulated that NMDA would enhance the osteoblastic cell's response to stretching. The goal of this study was to investigate, in the presence of the neurotransmitter NMDA, the effect of mechanical loading on osteoblast's stage of differentiation and the ...

The influence of transient forebrain ischemia on the temporal alteration of glutamate receptors in the hippocampal formation was analyzed by means of in vitro quantitative receptor autoradiography. We compared the binding of N-methyl-D-aspartate (NMDA) receptors using [3H]3-[+/-)2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP), noncompetitive NMDA antagonist binding sites using [3H]N-(1-...

In a synapse, spontaneous and action-potential-driven neurotransmitter release is assumed to activate the same set of postsynaptic receptors. Here, we tested this assumption using (+)-5-methyl-10,11-dihydro-5H-dibenzo [a,d] cyclohepten-5,10-imine maleate (MK-801), a well characterized use-dependent blocker of NMDA receptors. NMDA-receptor-mediated spontaneous miniature EPSCs (NMDA-mEPSCs) were ...

Previous work with recombinant receptors has shown that the identity of the NMDA NR2 subunit influences receptor affinity for both glutamate and glycine. We have investigated the developmental change in NMDA receptor affinity for both glutamate and glycine in acutely dissociated parietal cortex neurons of the rat, together with the expression during ontogeny of NR2A and NR2B mRNA and protein. W...

PURPOSE Kynurenic acid (KYNA), an endogenous tryptophan metabolite, is an N-methyl-D-aspartate (NMDA) antagonist active at the glycine-binding site of the NMDA-receptor complex. The authors investigated whether systemic administration of a biochemical precursor of KYNA, L-kynurenine (L-Kyn), could block NMDA- or kainic acid (KA)-induced cell death in adult rat retinal ganglion cells (RGCs) and ...

N-methyl-D-aspartate (NMDA) receptor-mediated excitotoxicity is one of the major causes for neuronal cell death during cerebral ischemic insult. Previously, we reported that the final product of lipid membrane peroxidation 4-hydroxy-2E-nonenal (HNE) synergistically increased NMDA receptor-mediated excitotoxicity (J Neurochem., 2006). In this study, we investigated the mechanism involved in the ...

Chronic exposure to lead (Pb) affects neural functions in central nervous system (CNS) particularly the learning and memory. On the other hand, alteration of calcium level in the CNS results in activation of NOS. It has been shown that lead enters the neurons through calcium channels and displaces Ca2+ from calcium binding proteins such as calmodulin and troponin C thereby affecting calcium-med...

Anti-N-Methyl-D-Aspartate-Receptor (NMDA-R) encephalitis is a new autoimmune disorder, often paraneoplastic in nature, presenting with complex neuropsychiatric symptoms. Diagnosed serologically, this disorder is often responsive to immunosuppressant treatment. We here in report the case of a 56-year-old man with anti NMDA-R encephalitis presenting initially with disorientation and hallucinati...

We have investigated the role of the N-methyl-D-aspartate (NMDA) receptor, a subtype of glutamate receptor, in the responses of cells in adult cat visual cortex. After intracortical infusion of the NMDA receptor antagonist DL-2-amino-5-phosphonovalerate (DL-APV) for one day, iontophoretic responses to NMDA, to kainate, and to quisqualate revealed a receptor blockade specific to NMDA receptors a...

Increasing data suggest that glutamate might act as a cell-signaling molecule in non-neuronal tissues such as the skin. Here we demonstrate the presence of functional N-methyl-D-aspartate (NMDA)-type glutamate receptors in human keratinocytes. NMDA receptor expression strongly reflects the degree of cell-to-cell contact. Wounding polarizes the expression of NMDA receptors in keratinocytes invol...