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Browsing ESS - CF - Artigos by Author "Alves, Cecília Juliana"
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- Ecstasy-induced oxidative stress to adolescent rat brain mitochondria in vivo: influence of monoamine oxidase type APublication . Alves, Ema; Summavielle, Teresa; Alves, Cecília Juliana; Custódio, José Barata Antunes; Fernandes, Eduarda; Bastos, Maria de Lourdes; Tavares, Maria Amélia; Carvalho, FélixThe administration of a neurotoxic dose of 3,4-methylenedioxymethamphetamine (MDMA; 'ecstasy') to the rat results in mitochondrial oxidative damage in the central nervous system, namely lipid and protein oxidation and mitochondrial DNA deletions with subsequent impairment of the correspondent protein expression. Although these toxic effects were shown to be prevented by monoamine oxidase B inhibition, the role of monoamine oxidase A (MAO-A) in MDMA-mediated mitochondrial damage remains to be evaluated. Thus, the aim of the present study was to clarify the potential interference of a specific inhibition of MAO-A by clorgyline, on the deleterious effects produced by a binge administration of a neurotoxic dose of MDMA (10 mg MDMA/kg of body weight, intraperitoneally, every 2 hours in a total of four administrations) to an adolescent rat model. The parameters evaluated were mitochondrial lipid peroxidation, protein carbonylation and expression of the respiratory chain protein subunits II of reduced nicotinamide adenine dinucleotide dehydrogenase (NDII) and I of cytochrome oxidase (COXI). Considering that hyperthermia has been shown to contribute to the neurotoxic effects of MDMA, another objective of the present study was to evaluate the body temperature changes mediated by MDMA with a MAO-A selective inhibition by clorgyline. The obtained results demonstrated that the administration of a neurotoxic binge dose of MDMA to an adolescent rat model previously treated with the specific MAO-A inhibitor, clorgyline, resulted in synergistic effects on serotonin- (5-HT) mediated behaviour and body temperature, provoking high mortality. Inhibition of MAO-A by clorgyline administration had no protective effect on MDMA-induced alterations on brain mitochondria (increased lipid peroxidation, protein carbonylation and decrease in the expression of the respiratory chain subunits NDII and COXI), although it aggravated MDMA-induced decrease in the expression of COXI. These results reinforce the notion that the concomitant use of MAO-A inhibitors and MDMA is counter indicated because of the resulting severe synergic toxicity.
- Exploratory behavior in rats postnatally exposed to cocaine and housed in an enriched environmentPublication . Magalhães, Ana; Melo, Pedro; Alves, Cecília Juliana; Tavares, Maria Amélia; Sousa, Liliana De; Summavielle, TeresaExposure to cocaine in early periods of postnatal life is usually associated with changes in development of neurotransmitter systems and structure of the central nervous system. Such changes are most likely correlated with behavioral alterations. Environmental enrichment conditions (EC) in early stages is a factor that affects structural and behavioral development. The purpose of this study is to examine the effects of EC on rats postnatally exposed to cocaine on exploratory behavior. Wistar rats were as signed to four groups—Group 1: pups exposed to cocaine hydrochloride (15 mg/kg body weight/day) s.c., in two daily doses, from postnatal day (PND) 1 to 28 and reared in EC; Group 2: pups exposed to cocaine as previously described and reared in a stan dard environmental conditions (SC); Group 3: pups saline-injected and reared in EC; and Group 4: pups saline-injected and reared in SC. On PND 21, 24, and 28, groups of four rats (to reduce anxiety) were placed for 10 minutes into an arena with sev eral objects. The following exploratory behavioral categories were examined: object interaction, exploration, manipulation, approximation, and total time of object contact. Animals from Group 2 showed decreased object interaction and total contact on PND 21. Control offspring reared in EE showed decreases in exploratory behavior at all ages analyzed compared with the control SE group, while cocaine-exposed animals reared in EC showed decreased object interaction, object approximation, and total exploratory behavior. The results in this group suggest that EC improved information acquisition and memory processes in animals postnatally exposed to cocaine.
- Hormonal, neurochemical, and behavioral response to a forced swim test in adolescent rats throughout cocaine withdrawalPublication . Alves, Cecília Juliana; Magalhães, Ana; Summavielle, Teresa; Melo, Pedro; Sousa, Liliana De; Tavares, Maria Amélia; Monteiro, PedroThe use of cocaine in adults has been linked to depression and/or anxiety. Several studies have shown an association between cocaine-primed craving and depressive symptoms. In animal models, the forced swim test (FST) is frequently used for screening depressive-like behavior. This study aimed to verify the presence of depression-like symptoms in adolescent rats after chronic cocaine exposure by analyzing behavior in a FST. The subsequent alterations in neurotransmitters and hypothalamus-pituitary-adrenal axis activity induced by this test were also analyzed. Both male and female adolescent Wistar rats were submitted to a chronic “binge” pattern of administration of cocaine hydrochloride, and subjects were tested in a forced swim test 2 days after cocaine's last administration. At the end of the behavioral test, trunk blood was collected for quantification of corticosterone plasma levels, and hypothalamus, prefrontal cortex, amygdala, and hippocampus were dissected for neurochemical determinations. No significant differences were found in the behavior on the FST of both males and females after withdrawal from chronic cocaine administration. Nevertheless, plasma levels of corticosterone were increased in cocaine-treated males, although not significantly (P= 0.065). In females cocaine failed to affect corticosterone levels. Of interest, neurochemical analyses showed that dopamine turnover was decreased in amygdala in cocaine-treated males (not significantly, P= 0.055). No significant differences were found on neurotransmitter levels in the other brain regions analyzed. Withdrawal from chronic cocaine administration during adolescence did not have a significant effect on stress-induced behavioral alterations, although the neurochemical response to the stressful situation provided by FTS seemed to be affected.