Excessive glutamate signaling can lead to excitotoxicity, a phenomenon whereby over-activation of glutamate receptors initiates neuronal death. In recent years, it has been shown that glutamate can be toxic to white-matter oligodendrocytes. Up to recently, the prevailing view was that oligodendrocyte excitotoxicity is mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) a...

Glutamate is extensively and relatively uniformly distributed in the central nervous system (CNS) and its effects mediated by two distinct groups of receptors including Ionotropic and metabotropic glutamate receptors. Concentration of glutamate in the nervous system is much higher than in other tissues. Glutamate receptors play an important role in synaptic transmission, neural plasticity and n...

D-Serine is an important signaling molecule throughout the central nervous system, acting as an N-methyl-D-aspartate (NMDA) receptor coagonist. This study investigated the D-serine modulation of non-NMDA ionotropic glutamate receptors expressed by inner retinal neurons. We first identified that the degradation of endogenous retinal D-serine, by application of D-amino acid oxidase, caused an enh...

Striatal binding of labeled glutamate to N-methyl-D-aspartate (NMDA) receptors, D,L-alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) to quisqualate receptors and kainate to kainate receptors was examined in rats which had received unilateral decortications or unilateral striatal quinolinic acid lesions. One week after decortication, there were no significant changes in NMDA, qui...

Introduction Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system. There are multiple receptors for glutamate: in addition to the fast transfer of information via the recently cloned receptors for AMPA [(RS)-y-amino-3hydroxy5 -methyl-4-isoxazolepropionate]/kainate [ l ] and the high-affinity kainate receptor [2], Ca+ influx via the post-synaptic N-methyl-i>...

Glutamatergic neurotransmission in the substantia nigra pars compacta and pars reticulata is mediated through N-methyl-d-aspartate and a-amino-3-hydroxy-5-methyl-4-isoxaline propionic acid/kainate (AMPA) type receptors as well as other glutamate receptors and is critical for basal ganglia functioning. A major glutamatergic input to the substantia nigra originates in the subthalamic nucleus, and...

Ionotropic glutamate receptors are ligand-gated ion channels that mediate excitatory synaptic transmission in the central nervous system. Based on their structural and pharmacological properties, ionotropic glutamate receptors can be divided into three groups, which include α-amino-3-hydroxy-5-methyl-4-isoxasolepropionic acid (AMPA) receptors, kainate receptors, and N-methyl-D-aspartate (NMDA) ...

Excessive signalling by excitatory neurotransmitters like glutamate and ATP can be deleterious to neurons and oligodendroglia, and cause disease. In particular, sustained activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), kainate and N-methyl-d-aspartate (NMDA) receptors damages oligodendrocytes, a feature that depends entirely on Ca(2+) overload of the cytoplasm and tha...

one of the major classes of ionotropic glutamate receptors is the class of n-methyl-d-aspartate receptors (nmdars). receptor activation recruits, via calcium signal transduction mechanisms which play important roles in oxidative metabolism, mitochondrial free radical production and occurrence of other mitochondrial factors which potentially contribute to excitotoxicity and neuronal death. in...

Recent reports suggest that kainate acting at presynaptic receptors reduces the release of the inhibitory transmitter GABA from hippocampal neurons. In contrast, in the hypothalamus in the presence of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptor antagonists [1-(4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine (GYKI 52466) and D,L-2-am...