Possible Interaction: Dopamine and Glutamate

“Substantial evidence supports an important role for the excitatory neurotransmitter L-glutamate as a modulator of dopamine release in the central nervous system.”

“Our findings imply that dopamine regulates the availability of l-glutamate in the developing striatum.”

“The cytotoxic effects of dopamine and L-glutamate were additive rather than synergistic, regardless of the incubation time used.”

“In the absence of Mg2+, dopamine at 200 microM (IC50 60 microM), inhibited in more than 50% the release of [3H]GABA induced by L-glutamate and NMDA, but not by kainate.”

“In control rats the L-glutamate elicited responses of six cells tested could be suppressed by dopamine whereas in lesioned rats three of the six cells tested were unresponsive to dopamine.”

“After incubation of the cells with dopamine for 3 min, the desensitization was significantly reduced and the agonists L-glutamate , quisqualate, or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid induced steady-state currents with amplitudes that were similar to the previously observed transient currents.”

“Both ASP and GLU produced a release response at a concentration range of 1 to 10 mM. GLU was generally less efficacious in increasing dopamine outflow; at 5 and 10 mM, the maximum effect exerted by GLU was significantly less than that observed with ASP.”

“These results suggest that in the nucleus accumbens, ASP and GLU may increase dopamine release through distinct mechanisms and that their stimulatory action is dependent on axonal impulse flow.”

“ L-glutamate and N-methyl-D-aspartate stimulated the release of newly-synthesized [3H]dopamine , which was completely inhibited by physiological concentrations of magnesium and by the selective and non-competitive antagonist MK-801.”

“Perfusion of 500 nM-5 mM GLU through the microdialysis probe was without an effect on DA outflow whereas 10 mM GLU resulted in a significant (295%) increase in the basal level of DA.”

“These studies suggest that high concentrations of GLU are required to enhance the extracellular concentration of DA in vivo.”

“This light evoked release of dopamine is inhibited by GABA and L-glutamate , whilst antagonists of these retinal transmitters stimulate release in the dark.”