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  • Prenatal exposure to cocaine and enriched environment
    Publication . Magalhães, Ana; Summavielle, Teresa; Melo, Pedro; Rosa, Rui; Tavares, Maria Amélia; Sousa, Liliana de
    Exposure to cocaine throughout gestation may produce several deleterious outcomes in the offspring that include effects on neurotransmitter systems and structure of the central nervous system. Such changes are most likely correlated with behavioral alterations. Environmental enrichment (EE) in early stages is a factor that affects structural and behavioral development. This article examines the effects, upon social interactions, of EE during the first month of life in rats prenatally exposed to cocaine. Wistar dams were subcutaneously exposed to 60 mg/kg of cocaine divided in two daily doses from gestational day (GD)8 to GD22. Pair-fed controls were given saline vehicle in the same protocol. Offspring were distributed to the different environments in four experimental groups. Group 1: offspring from dams prenatally exposed to cocaine as previously described and reared in EE from postnatal day (PND)1 to PND28; Group 2: pups from cocaine-exposed dams and reared in a standard environment (SE); Group 3: pups from pair-fed saline-exposed dams and reared in EE; Group 4: offspring from saline-exposed dams and reared in SE. On PND21, 24, and 28, rats were examined in several social behavioral categories (play fighting, social investigation, comfort behaviors, and solicitation to play) for 10 min. Animals reared in SE do not display any differences due to treatment in the behavioral categories analyzed. Control offspring reared in EE presented decreased play fighting, decreased solicitation to play, and decreased social investigation compared to the control SE group, while cocaine-exposed animals reared in EE did not present these variations. These results suggest that EE rearing may unmask hidden effects of prenatal cocaine exposure.
    2006-09-06Journal article Open access Show more
  • MDA in adolescent male rats - decreased serotonin in the amygdala and behavioral effects in the elevated plus-maze test
    Publication . Faria, Raquel; Magalhães, Ana; Monteiro, Pedro; Silva, Joana Gomes da; Tavares, Maria Amélia; Summavielle, Teresa
    Long-term behavioral consequences of the neurotoxicity produced by 3,4-methylenedioxymethamphetamine (MDMA) in the adolescent rat are still mostly unknown. Here, adolescent male rats (postnatal day 45 PND [45]) were exposed to 10 mg/kg of MDMA, intraperitoneally, every 2 h for 6 h. Controls were given 0.9% saline in the same protocol. Ten days after exposure, the behavioral effects of MDMA were assessed in the elevated plus-maze (n = 6 per group). After behavioral testing, animals were sacrificed and the amygdalae were dissected and processed for HPLC determination of dopamine (DA), serotonin (5-HT), and metabolites. Results showed a significant decrease in the 5-HT content (P < 0.05), but no significant alterations in DA or its metabolites. Behavioral observation in the elevated plus-maze showed a decreased number of entries in the unprotected arms (P < 0.05), which were correlated to the number of entries and time spent in the central platform. Rearing was also decreased (P < 0.05). No differences were observed in head dips, grooming, or number of entries in the protected arms of the apparatus. Therefore, we conclude that, as in the adult rat, exposure to MDMA in the adolescent rat is associated to long-term depletion of the 5-HT content and increased anxiety-like behavior.
    2006-09-06Journal article Open access Show more