Acute SSRI-induced anxiogenic and brain metabolic effects are attenuated 6 months after initial MDMA-induced depletion.
To assess the functional state of the serotonergic system, the acute behavioural and brain metabolic effect of SSRI antidepressants were studied during the recovery period after MDMA-induced neuronal damage. The effects of the SSRI fluoxetine and the serotonin receptor agonist meta-chloro-phenylpiperazine (m-CPP) were investigated in the social interaction test in Dark Agouti rats, 6 months after treatment with a single dose of MDMA (15 or 30 mg kg(-1), i.p.). At earlier time points these doses of MDMA have been shown to cause 30-60% loss in axonal densities in several brain regions. Densities of the serotonergic axons were assessed using serotonin-transporter and tryptophan-hydroxylase immunohistochemistry. In a parallel group of animals, brain function was examined following an acute challenge with either fluoxetine or citalopram, using 2-deoxyglucose autoradiographic imaging. Six months after MDMA treatment the densities of serotonergic axons were decreased in only a few brain areas including hippocampus and thalamus. Basal anxiety was unaltered in MDMA-treated animals. However, the acute anxiogenic effects of fluoxetine, but not m-CPP, were attenuated in animals pretreated with MDMA. The metabolic response to both citalopram and fluoxetine was normal in most of the brain areas examined with the exception of ventromedial thalamus and hippocampal sub-fields where the response was attenuated. These data provide evidence that 6 months after MDMA-induced damage serotonergic axons show recovery in most brain areas, but serotonergic functions to challenges with SSRIs including anxiety and aggression remain altered.
Department of Pharmacodynamics, Semmelweis University, Nagyvarad ter 4, 1089 Budapest, Hungary.
Rómeó D
RD
Andó
Csaba
C
Adori
Eszter
E
Kirilly
Eszter
E
Molnár
Gábor G
GG
Kovács
Linda
L
Ferrington
Paul A T
PA
Kelly
György
G
Bagdy
D000818:Animals; D001007:Anxiety / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D001369:Axons / Q000187:drug effects / Q000473:pathology; D001921:Brain / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D015283:Citalopram / Q000494:pharmacology; D005473:Fluoxetine / Q000494:pharmacology; D008297:Male; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000008:administration & dosage / Q000633:toxicity*; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D009483:Neuropsychological Tests; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D012701:Serotonin / Q000378:metabolism*; D018490:Serotonin Agents / Q000008:administration & dosage / Q000633:toxicity*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*; D012919:Social Behavior; D013997:Time Factors
D015283:Citalopram; D005473:Fluoxetine; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D010879:Piperazines; D012701:Serotonin; D018490:Serotonin Agents; D017366:Serotonin Receptor Agonists; D017367:Selective Serotonin Reuptake Inhibitors; C015068:1-(3-chlorophenyl)piperazine