Influências do ciclo estral sobre o desempenho de ratos no labirinto em cruz elevado

The Elevated plus maze is one of the most popular models to study animal anxiety. Anxiety can be influenced by physiological factors, such as the hormonal state. The aim of the present work is to investigate the relationship between estrus cycle and rat exploratory behavior in the elevated plus maze. The study made use of male (n = 13) and female rats (n = 61). The females had their estral phase identified and were divided into 3 groups according to their hormonal state: Proestrus (N = 23), Estrous (N = 19) and Diestrous (N = 19). All animals were submitted to a 5-min session in the elevated plus maze. The data indicate differences between the diestrus group and male group in the percentage of time spent in the open arms, but do not in the percentage of entries. Keywords: estral cycle; anxiety; elevated plus maze.