The excitatory neurotransmitter glutamate plays important roles in the mammalian brain, ranging from synaptic plasticity to memory. To mediate these functions, glutamate activates two types of receptors: ligand-gated channels and metabotropic receptors coupled to G-proteins. Both families of glutamate receptors share no sequence homology and possess original structural features compared with ot...

l-Glutamate is a major excitatory neurotransmitter that binds ionotropic and metabotropic glutamate receptors. Cerebral endothelial cells from many species have been shown to express several forms of glutamate receptors; however, human cerebral endothelial cells have not been shown to express either the N-methyl-D-aspartate (NMDA) receptor message or protein. This study provides evidence that h...

Recently, NMDA receptors (NMDARs) have been implicated in a cell contact-dependent suppression of sprouting in cultured Xenopus tectal neurons during an early period when neither AMPA/kainate (KA) receptors nor action potentials play a prominent role in cell-cell communication. We asked how the NMDA receptors function in the absence of the depolarizing effect of AMPA/KA receptor activity. We sh...

The selective glutamate metabotropic receptor agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD) was applied iontophoretically to cells in the rat primary somatosensory cortex (SI) in vivo. In contrast to other in vivo studies, distinct excitatory and depressant effects were observed. The excitatory responses could not be blocked by ionotropic antagonists, as evidence that t...

In central mammalian neurons, activation of metabotropic glutamate receptor type1 (mGluR1) evokes a complex synaptic response consisting of IP3 receptor-dependent Ca(2+) release from internal Ca(2+) stores and a slow depolarizing potential involving TRPC3 channels. It is largely unclear how mGluR1 is linked to its downstream effectors. Here, we explored the role of stromal interaction molecule ...

Long-term potentiation (LTP) is a reflection of synaptic plasticity that induced by specific patterns of synaptic activity and has an important role in learning and memory. The first clue of the potential role of glutamate receptors in LTP was in 1991 with the observation that the mGluR agonists 1-amino-1, 3-cyclopentanedicarboxylic acid (ACPD), increased LTP. Studies have shown that ACPD induc...

Prolonged modification of intrinsic neuronal excitability is gaining prominence as an activity-dependent form of plasticity. Here we describe a potential synaptic initiation mechanism for these changes in which release of the transmitter glutamate acts on kainate receptors to regulate the postspike slow afterhyperpolarization (sAHP). This action of synaptically released glutamate was occluded b...

Activation of cannabinoid CB1 receptors reduces glutamatergic synaptic transmission in the rodent striatum and is involved in the normal control of motor function by the basal ganglia. Here we investigated CB1 receptor regulation of glutamate release and uptake and synaptic transmission in the rat striatum. We show that CB1 receptor activation reduces both the release and uptake of [3H]glutamat...