Glutamatergic transmission at mossy fiber (MF) synapses on CA3 pyramidal neurons in the hippocampus is mediated by AMPA, kainate, and NMDA receptors and undergoes presynaptic modulation by metabotropic glutamate receptors. The recruitment of different receptors has thus far been studied by altering presynaptic stimulation to modulate glutamate release and interfering pharmacologically with rece...

In recent years great progress has been made in understanding the function of ionotropic and metabotropic glutamate receptors; their pharmacology and potential therapeutic applications. It should be stressed that there are already N-methyl-D-aspartate (NMDA) antagonists in clinical use, such as memantine, which proves the feasibility of their therapeutic potential. It seems unlikely that compet...

A rise in arterial Pco(2) stimulates breathing and sympathetic activity to the heart and blood vessels. In the present study, we investigated the involvement of the retrotrapezoid nucleus (RTN) and glutamatergic mechanisms in the Bötzinger/C1 region (Bötz/C1) in these responses. Splanchnic sympathetic nerve discharge (sSND) and phrenic nerve discharge (PND) were recorded in urethane-anesthetize...

Previous studies have demonstrated that ethanol and volatile anesthetics inhibit the function of some metabotropic (G protein-coupled) receptors, including the 5-hydroxytryptamine2 and muscarinic cholinergic receptors. The metabotropic glutamate receptors (mGluRs) show little sequence homology with most other metabotropic receptors and are important modulators of synaptic transmission in the ma...

A long-standing question in neurobiology is whether astrocytes respond to the neuronal release of neurotransmitters in vivo. To address this question, acutely isolated hippocampal slices were loaded with the calcium-sensitive dye Calcium Green-1 and the responses of the astrocytes to electrical stimulation of the Schaffer collaterals were monitored by confocal microscopy. To confirm that the re...

Dopamine- and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32) plays a central role in medium spiny neurons in the neostriatum in the integration of various neurotransmitter signaling pathways. In its Thr-34-phosphorylated form, it acts as a potent protein phosphatase-1 inhibitor, and, in its Thr-75-phosphorylated form, it acts as a cAMP-dependent kinase inhibitor. Here, we investigated gluta...

Circuitry of the cerebellar cortex is regionally and functionally specialized. Unipolar brush cells (UBCs), Purkinje cell (PC) synapses made by axon collaterals in granular layer, are both enriched areas that control balance eye movement. Here, we find a link between these specializations mice: PCs preferentially inhibit metabotropic glutamate receptor type 1 (mGluR1)-expressing UBCs respond to...

Purines and pyrimidines are indispensable molecules of life; they fundamental for genetic code bioenergetics. From the very early evolution life purines have acquired meaning damage-associated extracellular signaller purinergic receptors emerged in unicellular organisms. Ancestral purinoceptors P2X-like ionotropic ligand-gated cationic channels showing 20–40% homology with vertebrate P2X recept...

BACKGROUND Glutamate, the main excitatory neurotransmitter, is involved in learning and memory processes but at higher concentration results excitotoxic causing degeneration and neuronal death. Adenosine is a nucleoside that exhibit neuroprotective effects by modulating of glutamate release. Hypoxic and related oxidative conditions, in which adenosine and metabotropic glutamate receptors are in...

The metabotropic glutamate receptors are coupled to intracellular signal transduction via G-proteins and consist of a family of at least five different subtypes, termed mGluR1-mGluR5. We studied the signal transduction mechanism and pharmacological characteristics of the rat mGluR3 and mGluR4 subtypes in Chinese hamster ovary cells permanently expressing the cloned receptors. Both mGluR3 and mG...