Name: LAISA BARROSO RIBEIRO
Type: MSc dissertation
Publication date: 21/08/2015
Examining board:
Name |
Role |
|---|---|
| ATHELSON STEFANON BITTENCOURT | Co advisor * |
| LÍVIA CARLA DE MELO RODRIGUES | External Examiner * |
| RITA GOMES WANDERLEY PIRES | Internal Examiner * |
Summary: The perinatal maternal relationship has a fundamental importance in the development of healthy neural circuits that remain as mental bequest throughout life. In this sense, adverse events in this period have the potential to induce psychopathology in adulthood, increasing vulnerability to psychiatric disorders and substance abuse. In this study, the Maternal Separation (MS) was performed in male Wistar rats, with the intention to mimic a sustained stress in human childhood. After that, the animals were submitted to the Environmental Enrichment protocol, a non-pharmacological strategy employed during a strong brain plasticity period, in order to prevent the harmful effects of MS. In adulthood, we proceeded to the behavioral tests for evaluate depression, anxiety and alcohol abuse, as well as biochemical tests as the analysis of plasmatic corticosterone, indicative of the reactivity of the hypothalamus-pituitary-adrenal (HPA) axis to acute stress, and analysis dopamine and metabolites in structures involved in brain reward process the mesocorticolimbic way (nucleus accumbens and prefrontal cortex). Statistical analysis was performed using the Student t test and one-way, two-way, three-way or repeated measures analysis of variance (ANOVA). We found that a more extensive SM protocol have greater impact on the development of depressive behavior in adulthood. We did not observe hyperresponsiveness of the HPA axis in separated animals in response to acute stress. EA increased the preference for sucrose consumption and SM and EA concurrently increased the active behaviors in the forced swimming test, suggesting antidepressant potential of the EA. EA appears to have anxiolytic potential to reduce learned anxiety in response to an aversive odor in the Predator Odor Test, and we observed no significant effect of SM in these behaviors. MS increases the preference for ethanol consumption, and EA was able to prevent this effect. In the prefrontal cortex, SM increased the amount of dopamine and EA increased dopaminergic turnover, suggesting a limited recovery of dopaminergic cortical activity. In the nucleus accumbens, SM and EA concurrently reduced DOPAC levels, without altering the dopaminergic turnover. SM and EA appear do not interfere with short and long-term memories. Thus, we observed through behavioral and biochemical changes that adverse events perinatal increase vulnerability to developing alcohol abuse and other psychiatric disorders in adulthood; the EA, employee in neural plasticity phase, has the potential to exert effect compensatory on generated deficits.
