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Regionally and functionally distinct serotonin 3 receptors control in vivo dopamine outflow in the rat nucleus accumbens
Author(s) -
De Deurwaerdère Philippe,
Moison Delphine,
Navailles Sylvia,
Porras Grégory,
Spampinato Umberto
Publication year - 2005
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2005.03174.x
Subject(s) - nucleus accumbens , chemistry , dorsal raphe nucleus , endocrinology , serotonin , medicine , dopamine , 5 ht receptor , agonist , pharmacology , stimulation , receptor , biology , serotonergic
Central serotonin 3 (5‐HT 3 ) receptors control the mesoaccumbens dopamine (DA) pathway. This control is thought to be conditional and might involve regionally distinct subpopulations of 5‐HT 3 receptors. Here, using in vivo microdialysis in rats, we assessed the relative contribution of nucleus accumbens (Nacc) 5‐HT 3 receptors to the overall influence exerted by 5‐HT 3 receptors on accumbal DA release induced by different drugs or treatments. In freely moving rats, pre‐treatment with 5‐HT 3 antagonists (0.1 mg/kg ondansetron and/or 0.03 mg/kg MDL 72222, s.c.) reduced DA efflux enhanced by morphine (1–10 mg/kg, s.c.) and haloperidol (0.01 mg/kg, s.c.), but not amphetamine (1–2.5 mg/kg, i.p.) or cocaine (10–20 mg/kg, i.p.), the latter two drugs do not trigger depolarization‐stimulated DA exocytosis. Intra‐Nacc administration of ondansetron (1 µ m ) in freely moving rats reduced the DA effects elicited by 10 mg/kg morphine, but not 1 mg/kg morphine or haloperidol. The 5‐HT 1A agonist 8‐OH‐DPAT (0.1 mg/kg, s.c.), known to decrease central 5‐HT tone, reduced 10 but not 1 mg/kg morphine‐stimulated DA outflow in freely moving rats. In halothane‐anaesthetized rats, intra‐Nacc ondansetron (1 µ m ) application reduced dorsal raphe nucleus electrical stimulation (20Hz)‐induced DA outflow. Our results show that regionally distinct populations of 5‐HT 3 receptors control the depolarization‐dependent exocytosis of DA and suggest that the involvement of Nacc 5‐HT 3 receptors occurs only when central DA and 5‐HT tones are concomitantly increased.