caa a22 4500 469079614 CHVBK 20180323132946.0 cr unu---uuuuu 170328e19920501xx s 000 0 eng 10.1007/BF00168943 doi (NATIONALLICENCE)springer-10.1007/BF00168943 The release of dopamine from nerve terminals and dendrites of nigrostriatal neurons induced by excitatory amino acids in the conscious rat [Elektronische Daten] [B.H.C. Westerink, M. Santiago, J.B. De Vries] Summary: The possible localization of excitatory amino acid (EAA) receptors on dopaminergic neurons was studied by microdialysis in conscious male rats. Varying concentrations of 3 specific EAA agonists, N-methyl-D-aspartate (NMDA), kainate and amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA), were infused into the striatum or into the substantia nigra, and the extracellular dopamine (DA) was recorded by the same probe. All 3 compounds induced a dose-dependent increase in both striatal and nigral extracellular DA. Kainate and AMPA were more potent than NMDA. Nigral DA release was stimulated by lower concentrations of kainate and AMPA than striatal DA release. The effects of two concentrations of NMDA and kainate on the release of DA were analyzed in terms of tetrodotoxin (TTX) dependency and sensitivity to ibotenic acid-induced striatal lesion. It appeared that NMDA and kainate stimulated DA release by 3 different mechanisms. The first mechanism is seen at low concentrations of kainate, it fulfills the criteria for a functional receptor-interaction: it is TTX-sensitive and independent of the ibotenic acid lesion. The second mechanism was observed when relatively low concentrations of NMDA stimulate the release of DA; in this effect postsynaptic structures are involved. The third mechanism lacks specificity as it is seen after high concentrations of kainate as well as of NMDA. The latter mechanism is TTX-independent and is probably of a toxic nature. Finally NMDA and kainate were infused into the nigra, whereas DA was recorded with a second probe implanted into the striatum. Kainate and NMDA induced an increase of striatal DA, but kainate was about 100 times more potent in this model than NMDA. The present data therefore support localization of kainate and (probably) AMPA-receptors on nigrostriatal dopaminergic neurons. The receptors on the somatoden-dritic sites were observed to be more sensitive than those on the nerve terminals. Springer-Verlag, 1992 Dopamine nationallicence Substantia nigra nationallicence Striatum nationallicence Excitatory amino acid receptors nationallicence Microdialysis nationallicence Westerink B.H.C. University Centre for Pharmacy, Department of Medicinal Chemistry, University of Groningen, Antonius Deusinglaan 2, NL-9713, AW Groningen, The Netherlands aut Santiago M. Department of Biochemistry, Faculty of Pharmacy, University of Sevilla, Sevilla, Spain aut De Vries J.B. University Centre for Pharmacy, Department of Medicinal Chemistry, University of Groningen, Antonius Deusinglaan 2, NL-9713, AW Groningen, The Netherlands aut Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 345/5(1992-05-01), 523-529 0028-1298 345:5<523 1992 345 210 https://doi.org/10.1007/BF00168943 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00168943 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Westerink B.H.C. University Centre for Pharmacy, Department of Medicinal Chemistry, University of Groningen, Antonius Deusinglaan 2, NL-9713, AW Groningen, The Netherlands aut NATIONALLICENCE 700 1- Santiago M. Department of Biochemistry, Faculty of Pharmacy, University of Sevilla, Sevilla, Spain aut NATIONALLICENCE 700 1- De Vries J.B. University Centre for Pharmacy, Department of Medicinal Chemistry, University of Groningen, Antonius Deusinglaan 2, NL-9713, AW Groningen, The Netherlands aut NATIONALLICENCE 773 0- Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 345/5(1992-05-01), 523-529 0028-1298 345:5<523 1992 345 210 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer