Banca de QUALIFICAÇÃO: JÚLIO MACHADO DA CÂMARA NETO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : JÚLIO MACHADO DA CÂMARA NETO
DATE: 12/12/2025
TIME: 14:00
LOCAL: Videoconferência
TITLE:

Effects of exposing rats to the Open Elevated Plus Maze during the first phase of the Formalin Test

KEY WORDS:

Elevated Plus-Maze; Antinociception; Formalin Test; Fear; Stress.

PAGES: 56
BIG AREA: Ciências Biológicas
AREA: Fisiologia
SUMMARY:

Animals exposed to innate or learned threatening environments exhibit defensive behaviors, promoting
their self-preservation. Frequently, among behavioral responses, animals exhibit Fear-Induced
Antinociception (FIA). In experimental models, the combination of the Elevated Plus Maze (EPM) with the
Formalin Test is relevant for understanding the mechanisms underlying FIA. However, despite studies
investigating antinociception during the second phase of the formalin test, there is a gap in knowledge
about its occurrence in the first phase. In this sense, the objective of this research is to investigate the
effect of exposing rats to the EPM during the first phase of the formalin test. Furthermore, the influence
of repeated exposures to the EPM on nociception was evaluated. For this, 95 adult Wistar rats (2 to 3
months) were used. In the first experiment, the animals (n=25) received a formalin injection and were
exposed to three different environments: Glass Box (controls), closed EPM (EPMc) or open EPM (EPMo)
during the initial five minutes of the test. In the second experiment, the animals were divided into five
groups (n=7 per group): those exposed one, two, three, four, or six times to the EPMc or EPMo. The
results of the first experiment revealed a statistical difference (using one-way ANOVA) between the
different types of environments (p<0.01) with Tukey's post hoc test revealing differences between the
EPMo and Control groups (p<0.05) and between EPMo and EPMc (p<0.05). Furthermore, the Student's T
test revealed a statistical difference between the first and second phase of the formalin test for the
animals exposed to the EPMo during the first phase and, subsequently, transferred to the glass box and
evaluated in the second phase (p<0.01). In the second experiment, the two-way ANOVA revealed a
statistical difference for the factor "type of maze" (EPMc or EPMo) (p<0.001), while values for the factor
"days of exposures" did not reveal a statistically significant difference. These results showed that
antinociception induced by the EPMo occurred during the first phase of the formalin test, and repeated
exposures to the EPMo did not alter the nociceptive response. Therefore, it is suggested that, based on
the second experiment, the analgesia induced by the EPMo seems to be produced by non-opioid
mechanisms.

COMMITTEE MEMBERS:
Presidente - 2121895 - ALIANDA MAIRA CORNELIO DA SILVA
Interno - 3550124 - JUDNEY CLEY CAVALCANTE
Interna - 1720860 - VANESSA DE PAULA SOARES RACHETTI