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Influence of serotoninergic drugs on in vivo dopamine extracellular output in rat striatum
Author(s) -
Santiago Marti,
Matarredona Esperanza R.,
Machado Alberto,
Cano Josefina
Publication year - 1998
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/(sici)1097-4547(19980601)52:5<591::aid-jnr11>3.0.co;2-5
Subject(s) - microdialysis , nomifensine , extracellular , agonist , serotonergic , clomipramine , chemistry , pharmacology , endocrinology , medicine , serotonin , dopamine , receptor , biology , dopaminergic , biochemistry
In vivo microdialysis was used to investigate the mechanism behind the increase in extracellular dopamine (DA) induced by increase in extracellular serotonin (5‐HT) level and 5‐HT 1 and 5‐HT 2 receptor activation. The following serotoninergic drugs were perfused in the absence or presence of nomifensine (5 μM)or tetrodotoxin (TTX; 2 μM): clomipramine (10, 500 and 1,000 μM), a selective 5‐HT reuptake inhibitor; 8‐OH‐DPAT (50 and 500 μM), a 5‐HT 1A receptor agonist; and α‐methyl‐5‐HT (1, 5 and 50 μM), a 5‐HT 2 receptor agonist. All the serotoninergic drugs studied increased DA extracellular output in a dose‐dependent manner. The presence of nomifensine attenuated the effect of perfusion of clomipramine (500 μM) and completely abolished the effect of perfusion of 8‐OH‐DPAT (500 μM) and α‐methyl‐5‐HT (5 μM) on DA extracellular output. Clomipramine (100–1,000 μM) perfusion produced a dose dependent increase in DOPAC extracellular output, which was stronger when clomipramine (500 μM) was co‐perfused with nomifensine. 8‐OH‐DPAT and α‐methyl‐5‐HT perfusion decreased DOPAC overflow. Addition of TTX to the perfusion fluid one hour before serotoninergic drugs perfusion, did not completely abolish the effect on dopamine extracellular output produced by the serotoninergic drugs. These data seem to indicate that increase in extracellular 5‐HT level and 5‐HT 1 and 5‐HT 2 receptor activation increase in vivo DA extracellular output in the striatum mainly by a non‐exocytotic mechanism involving DA uptake sites and, secondarily, by activation of 5‐HT receptors. J. Neurosci. Res. 52:591–598, 1998. © 1998 Wiley‐Liss, Inc.