Neuron aspartate

Grb-2 facilitates the transduction of an extracellular stimulus to an intracellular signaling pathway, (b) The adaptor protein PSD-95 associates through one of its three PDZ domains with the N-methyl-D-aspartic acid (NMDA) receptor. Another PDZ domain associates with a PDZ domain from neuronal nitric oxide synthase (nNOS). Through its interaction with PSD-95, nNOS is localized to the NMDA receptor. Stimulation by glutamate induces an influx of calcium, which activates nNOS, resulting in the production of nitric oxide. 

On the pathophysiological side, hyperactive nNOS has been implicated in A/-methyl-D-aspartate (NMDA)-receptor-mediated neuronal death in cerebrovascular-stroke. Some disturbances of smooth muscle tone within the gastrointestinal tract (e.g., gastroesophageal reflux disease) may also be related to an overproduction of NO by nNOS in peripheral nitrergic nerves. 

These include nicotinic acetylcholine receptors, neuronal calcium channels, muscle sodium channels, vasopressin receptors, and iV-methyl-D-aspartate (NMDA) receptors. Some general features of the structure, function, and evolution of biologically active peptides isolated from Conus venom are presented. 

Deiva K, Geeraerts T, Salim H, Leclerc P, Hery C, Hugel B, Freyssinet JM, Tardieu M (2004) Fractalkine reduces N-methyl-d-aspartate-induced calcium flux and apoptosis in human neurons through extracellular signal-regulated kinase activation. Eur J Neurosci 20(12) ... 

While aspartic acid (aspartate) is also found in the CNS and has excitatory effects on neurons, little is known of its precise location and action although it may be released from intrinsic neurons and hippocampal pathways. It will not be discussed further. 

While there are some reports of increased NMDA and non-NMDA receptor number in various cortical regions of schizophrenics including the prefrontal cortex, there are also indications of impaired glutamate innervation, such as reduction in its neuronal uptake sites (Ishimaru, Kurumaji and Torn 1994). Also it has been found that levels of the mRNA for the NRI subunit of the NMDA receptor in the hippocampus and its D-aspartate binding sites in the temporal cortex are both reduced more on the left than right side in schizophrenic brain. This is another indication of greater malfunction on the left side of the brain and the possibility that some schizophrenic symptoms arise from an imbalance between cross-cortical activity. 

Anis, N.A. Berry, S.C. Burton, N.R. and Lodge, D. The dissociative anaesthetics, ketamine and phencyclidine selectively reduce excitation of central mammalian neurones by N-methyl-aspartate. Bj J. Pharmacol 79 565-575, 1983. 

Status epilepticus occurs because the brain fails to stop an isolated seizure. The exact reason for this failure is unknown and probably involves many mechanisms. A seizure is likely to occur due to a mismatch of excitatory and inhibitory neurotransmitters in the brain. The primary excitatory neurotransmitter in the brain is glutamate. Glutamate stimulates postsynaptic N-methyl-D-aspartate (NMDA) receptors in the brain, causing an influx of calcium into the cells and depolarization of the neuron. Sustained depolarization may maintain SE and eventually cause neuronal injury and death.7 The primary... 

Ascher P. and Nowak L., The role of divalent cations in the IV-methyl-D- aspartate responses of mouse central neurones in culture, J. Physiol., 399, 247-266, 1988. 

Ibogaine protects the N-methyl-D-aspartate neuron receptors against excessive release of excitatory amino acids and represents, therefore, a potential therapeutic agent for the treatment of Alzheimer s disease, Huntington s chorea, and other... 

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