Synaptosomal glutamate release

Collard KJ, Edwards R, Liu Y (1993) Changes in synaptosomal glutamate release during postnatal development in the rat hippocampus and cortex. Dev Brain Res 77 37-43. 

In an extension to the studies mentioned above, the actions of 11 commercial pyrethroids on calcium influx and glutamate release were assessed using a high-throughput approach with rat brain synaptosomes [75, 76]. Concentration-dependent response curves for each commercial pyrethroid were determined and the data used in a cluster analysis. Previously characterized Type II pyrethroids that induce the CS-syndrome symptoms (cypermethrin, deltamethrin, and esfenvalerate) increased calcium influx and glutamate release, and clustered with two other ot-cyano pyrethroids (p-cyfluthrin and A-cyhalothrin) that shared these same actions. Previously characterized Type I pyrethroids (bioallethrin, cismethrin, and fenpropathrin) did not share these actions and clustered with two other non-cyano pyrethroids (tefluthrin and bifenthrin) that likewise did not elicit these actions. 

It was also demonstrated that acute exposure to diphenyl ditelluride did not change [ H]glutamate release and uptake by rat brain synaptosomes. In contrast, in vitro experiments indicate that 100 am of diphenyl ditelluride clearly inhibit [ H]glutamate uptake by brain synaptosomes and synaptic vesicles. These results also suggested that the inhibitory effect on glutamate uptake may be related, at least in part, to the ability of this compound to oxidize thiol groups. ... 

Lynch M. A. and Voss K. L. (1990). Arachidonic acid increases inositol phospholipid metabolism and glutamate release in synaptosomes prepared from hippocampal tissue. J. Neurochem. 55 215-221. 

Bannister RA, Melliti K, Adams BA (2004) Differential modulation of CaV2.3 Ca2+ channels by Galphaq/11-coupled muscarinic receptors. Mol Pharmacol 65 381-8 Barclay JW, Craig TJ, Fisher RJ et al (2003) Phosphorylation of Muncl8 by protein kinase C regulates the kinetics of exocytosis. J Biol Chem 278 10538—45 Barrie AP, Nicholls DG, Sanchez-Prieto J et al (1991) An ion channel locus for the protein kinase C potentiation of transmitter glutamate release from guinea pig cerebrocortical synaptosomes. J Neurochem 57 1398-1404... 

Wang SJ, Sihra TS (2003) Opposing facilitatory and inhibitory modulation of glutamate release elicited by cAMP production in cerebrocortical nerve terminals (synaptosomes). Neuropharm 44 686-97... 

The control of dopamine release via presynaptic nAChRs has been investigated in great detail. Originally, modulation of dopamine release via nAChRs has been revealed in striatal synaptosomes (Rapier et al. 1990). More recently, the receptors involved have been documented to contain 0C4, 0C5, a, P2, and p3 subunits (Luetje 2004 Salminen et al. 2004). Although 0C7 containing receptors were found to contribute to the facilitation of dopamine release, this was due to an indirect effect mediated by increases in glutamate release (Kaiser and Wonnacott 2000). In other... 

Silva Brum, L. F., Emanuelli, T., Souza, D. O., and Elisabetsky, E. (2001). Effects of linalool on glutamate release and uptake in mouse cortical synaptosomes. Neurochem. Res. 26, 191—194. 

Li X, Clark JD (2003) Heme oxygenase type 2 participates in the development of chronic inflammatory and neuropathic pain. J Pain 4 101-107 Li X, Eisenach JC (2001) Alpha2A-adrenoceptor stimulation reduces capsaicin-induced glutamate release from spinal cord synaptosomes. J Pharmacol Exp Ther 299 939-944 Li X, Eisenach JC (2002) Nicotinic acetylcholine receptor regulation of spinal norepinephrine release. Anesthesiology 96 1450-1456... 

It is interesting to notice that the characterization of the cellular and molecular mechanisms of the star fruit intoxication needs to pass through a group of different experimental protocols among them in vivo and the in vitro bioassays. The correlation between in vivo and in vitro models is then more complex that we should think it is [53]. Thus, the particular case of synaptosomes and GABA and glutamate release and re-uptake, shows neurochemical dynamics associated to star fruit intoxication mechanisms in a preparation which consists of isolated synaptic terminals (44). However, additional studies are needed with brain slices from control brains treated with the AcTx and even the use of ex vivo models in vitro bioassays from tissue after in vivo experiments), for example, in our case, brain slices from treated animals. 

Fig. 3. Release of glutamate from rat brain synaptosomes with 50 mM KCI depolarization using the fluorometric assay described in the text. Ca -dependent glutamate release was inhibited by pre-incubating the synaptosomes with active BoNT/Cl (100 nM) for 90 min at37°C...

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