Banca de DEFESA: RAFAEL DOS SANTOS DE BESSA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : RAFAEL DOS SANTOS DE BESSA
DATE: 06/04/2023
TIME: 13:00
LOCAL: https://meet.google.com/cpg-dees-xnz
TITLE:

THE ONTOGENY OF ULTRASONIC VOCALIZATIONS IN AN ANIMAL MODEL OF AUTISM

KEY WORDS:

Autism; USV; Postnatal development; 40 kHz USVs; USV classification; open field

PAGES: 158
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

Communication during social interaction is a key factor in choosing the most fitting behavioral response in each situation. Rats vocalize at the ultrasound range (USVs) to convey information on their emotional states and to engage in social interaction. The adult vocal repertoire is developmentally established by the maturation of innate neonatal 40-kHz calls elicited under stressful situations, which evoke maternal care responses towards the pup. Understanding how emission patterns and acoustic properties change with aging can help us to identify abnormality signs of developmental disorders such as autism. Here, we analyzed the postnatal development of acoustic parameters and emission patterns of isolation-induced USVs produced by infant rats prenatally exposed to valproic acid (VPA) during the first three weeks of life. We also investigate the effects of VPA exposition over vocal production. Our result showed a reduction in emissions of VPA-exposed animals and alterations in the acoustic parameters and emission patterns compared to control animals. After applying two different classification methods, a convolution neural network (CNN) and a gaussina mixture model (GMM), to spectro-temporally distinguish
individual USVs, we found a significant reduction in the number of vocal classes in the animals with autistic phenotype. Complexity of emissions, measured by the degrees of possible transitions between pairs of USVs, were also dramatically reduced in those animals, indicating a less diverse vocal repertoire compared to controls. By the end of the third postnatal week, when animals were weaned, we evaluated exploratory behavior during the open-field test. VPA-treated animals showed reduced exploratory behaviors. Behavioral analyses showed a positive correlation between the amount of frequency modulated calls and exploratory behavior in the open-field, in contrast to a negative correlation between non-modulated calls and this behavior. In conclusion, VPA-treated rats display an abnormal vocal development characterized not only by quantitative reduction in vocal production but also by altered bioacoustic and dynamical vocalization patterns, which correlates to post-weaning behavior.

COMMITTEE MEMBERS:
Externo à Instituição - RAFAEL NAIME RUGGIERO - USP
Externo à Instituição - CLEITON LOPES AGUIAR - UFMG
Interno - 3086031 - DANIEL YASUMASA TAKAHASHI
Externa à Instituição - REGINA HELENA DA SILVA - UNIFESP
Presidente - 1698305 - RODRIGO NEVES ROMCY PEREIRA