CNR ExploRA

Articolo in rivista, 2017, ENG, 10.1016/j.neuropharm.2017.06.008

Widespread reduction of dopamine cell bodies and terminals in adult rats exposed to a low dose regimen of MDMA during adolescence

Cadoni C.; Pisanu A.; Simola N.; Frau L.; Porceddu P.F.; Corongiu S.; Dessi C.; Sil A.; Plumitallo A.; Wardas J.; Di Chiara G.

National Research Council of Italy, Institute of Neuroscience, Cagliari Section, , Italy; Department of Biomedical Sciences, Neuropsychopharmacology Section, University of Cagliari, Cagliari, , Italy; Centre of Excellence "Neurobiology of Dependence", University of Cagliari, Cagliari, , Italy; Department of Life and Environmental Sciences, University of Cagliari, Cagliari, , Italy; Department of Neuropsychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, Krakow, , , Poland; Department of Neuropsychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, Krakow, , , Poland

Although MDMA (3,4-methylendioxymethamphetamine, ecstasy) neurotoxicity in serotonin neurons is largely recognized in a wide variety of species including man, neurotoxicity in dopamine (DA) neurons is thought to be species-specific. MDMA is mainly consumed by adolescents, often in conjunction with caffeine (Energy Drinks) and this association has been reported to exacerbate MDMA toxic effects. In order to model these aspects of MDMA use, vis-à-vis their impact on DA neurons, we investigated the effects of adolescent exposure to low doses of MDMA (5 mg/kg for 10 days), alone or in combination with caffeine (10 mg/kg) on neuronal and functional DA indices and on recognition memory in adult rats. MDMA reduced density of tyrosine hydroxylase (TH) positive neurons in the ventral tegmental area and in the substantia nigra pars compacta, and immunoreactivity of TH and DA transporter in the nucleus accumbens (NAc) shell and core, and caudate-putamen. This same treatment caused a reduction of basal dialysate DA in the NAc core. MDMA-pretreated rats also showed behavioral sensitization to a MDMA challenge at adulthood and potentiation of MDMA-induced increase of dialysate DA in the NAc core, but not in the NAc shell. In addition, MDMA-treated rats displayed a deficit in recognition memory. Caffeine co-administration did not affect the above outcomes. Our results show that adolescent exposure of rats to low doses of MDMA induces long-lasting and widespread reduction of DA neurons indicative of a neurotoxic effect on DA neurons and suggestive of a degeneration of the same neurons.

Neuropharmacology (Online) 123 , pp. 385–394