Banca de DEFESA: CATIA MELO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : CATIA MELO
DATA : 29/06/2022
HORA: 14:00
LOCAL: Remoto
TÍTULO:

Effects of depression on the susceptibility of developing symptoms associated with Alzheimer's Disease of sporadic origin in Wistar rats

PÁGINAS: 50
GRANDE ÁREA: Ciências Biológicas
ÁREA: Biologia Geral
RESUMO:

Alzheimer's disease (AD) is the most common dementia associated with aging and is accompanied by neurodegeneration with impaired cognitive functions. A very common comorbidity is major depression, a serious mood disorder that is a major cause of disability worldwide. Both pathologies are associated with variations in body temperature (Tc). The aim of the present work is to evaluate whether depression induced by maternal separation (MS) can influence the development of memory and thermoregulation disorders associated with an experimental model for sporadic Alzheimer's disease using streptozotocin (STZ) in Wistar rats.The animals were submitted to MS from the 2nd to the 14th day after birth for 3 hours daily. At 2 months of age, the animals were submitted to behavioral tests: elevated plus maze, open field and forced swimming, for the analysis of possible exploratory or passive behaviors. Subsequently, a surgical procedure was performed for datalogger placement and intracerebroventricular (icv) injection of STZ or vehicle. To check for possible impairments of working memory and learning, after 30 days the animals were submitted to the Barnes maze and, then, to thermoregulatory tests such as the analysis of Tcs to calculate the heat loss index, in the exposure to cold and to heat and behavior when the choice of soil temperature is allowed. After euthanasia, the brains were perfused to perform sections and verify the brain ventricular volume. The animals submitted to MS showed less time spent in the open arms of the elevated plus maze and in the center of the open field and less motivation in the forced swimming test. In the Barnes maze, animals treated with STZ showed memory and learning impairment when compared to animals treated with vehicle. SM resulted in memory impairments compared to controls, but did not accentuate the effects of STZ. In the thermoregulatory tests, it was observed that animals submitted to SM treated with STZ had higher Tcs when compared to those treated with vehicle between days 21 and 27 after the surgical procedure. Regarding the heat loss index, it was observed that the animals treated with STZ showed less heat loss when compared to those treated with vehicle, showing greater vasoconstriction. There was no effect of the thermoregulatory response on exposure to cold or heat. In the temperature selection challenge, animals treated with STZ had a preference for neutral temperature (26ºC) compared to cold temperature (18ºC), both in the control group and in the SM group. No differences were observed in the neutral temperature (26ºC) and warm temperature (32ºC) challenge. After euthanasia, it was observed that animals treated with STZ had greater ventricular volume when compared to animals treated with vehicle. In conclusion, animals submitted to MS did not show more pronounced responses to the deleterious effect of STZ, which shows that the development of symptoms related to depression and anxiety does not necessarily potentiate memory impairments related to sporadic AD.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1762353 - MARIA CAMILA ALMEIDA
Membro Titular - Examinador(a) Interno ao Programa - 1893240 - RAQUEL VECCHIO FORNARI
Membro Titular - Examinador(a) Interno ao Programa - 1771857 - CARLOS ALBERTO DA SILVA
Membro Titular - Examinador(a) Externo à Instituição - SAMYR MACHADO QUEROBINO
Membro Titular - Examinador(a) Externo à Instituição - ROBSON CRISTIANO LILLO VIZIN
Membro Suplente - Examinador(a) Interno ao Programa - 1994696 - SILVIA HONDA TAKADA
Membro Suplente - Examinador(a) Externo à Instituição - NÚBIA MANTOVAN FARDIN - UNIP