Name: VANESSA GHIDETTI ALVARENGA TELLES
Type: MSc dissertation
Publication date: 16/09/2016
Examining board:
Name |
Role |
|---|---|
| ATHELSON STEFANON BITTENCOURT | Internal Alternate * |
| JULIANA BARBOSA COITINHO GONCALVES | Internal Examiner * |
| LÍVIA CARLA DE MELO RODRIGUES | Co advisor * |
Summary: Early life stress can generate long-lasting effects on brain and behavior during adulthood. Furthermore, stressful experiences stimulate abusive consumption of ethanol, which induces neuronal damages and contributes to increases on parameters of oxidative stress on Central Nervous System. The aim of this research was to evaluate the effects of Maternal Separation (MS) and of intermittent ethanol binge drinking in adolescent rats on behavioral and oxidative stress parameters. Pregnant Wistar rats were used. After birth of litters, the animals were divided into control group (NS) or maternal separation group (MS). Maternal separation was performed from 2 to 15 postnatal day, 3 hours daily. At postnatal day 35, animals were divided again into 3 groups: animals which received intragastric saline (vehicle group) or ethanol in doses of 3.0 or 6.0 g/kg. Ethanol was administered once a day, in a regimen of two consecutive days interspersed by two days without ethanol, totalizing 10 doses for chronic binge treatments. Acute binge exposure happened at postnatal day 35 until 37 postnatal day. At the end of this procedure the animals were subjected to behavioral tests or euthanized for obtaining structures. Memory was accessed by object recognition test and by Y maze test, and hippocampi and pre frontal cortex were dissected. Only from animals submitted to chronic binge treatment, for evaluation of lipid peroxidation (LP), oxidative species production (ROS), and enzymatic activity of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx). We observed a significant interaction between factors on short-term memory of Object Recognition Test (OR), and an influence of MS on the acquisition phase during Y maze test on the animals submitted chronic binge treatment. In animals submitted to acute binge exposure we observed effect of MS and of ethanol on long-term memory of OR. Furthermore, our results showed that MS induced an increase in SOD activity, ROS and LP, decreasing GPx activity, as well as an interaction between factors in CAT activity on hippocampus. In pre frontal cortex, our results to show that MS induced an increase in GPx activity and lipid peroxidation. To summarize, we found an interaction between MS and ethanol as contributing factors for cognitive impairment in short-term memory and long-term memory. Besides, maternal separation was able to induce oxidative stress in PFC and hippocampus, but this parameter was not influenced by ethanol chronic binge treatment.
