Comparison of female and male behavior in the elevated gradient of aversion

Abstract

The elevated gradient of aversion (EGA) is an apparatus for investigating the exploratory behavior of rats in 3-min sessions, consisting of three different sections of the same size: tunnel, closed arm, and open arm. Factorial analyses have defined three factors: exploration, impulsivity, and self-protection. In general, male rats are placed in the tunnel end and tend to hesitate leaving this starting point. Then, they hesitate leaving the tunnel and entering the closed arm, which they explore and tend to avoid entering the open arm or even just stick their head in and not enter it at all. Since females were not used for this test and are reported to be more explorative than male rats, the present work aimed to compare the behavior of male and female rats in the EGA. Thirty male and 34 female Wistar rats were submitted to 3-min sessions in the EGA. In general, results indicated that females were different from males: they explored more (Factor 1 -Exploration), are more impulsive (Factor 2 -Impulsivity), and are less anxious/fearful (Factor 3 -Self-protection). These results confirmed the results of other studies obtained with other apparatuses and show that females exhibit higher locomotion than males and are less anxious/fearful.

Comparison of exploratory behavior of male and female woodlice (Armadillidium vulgare)

“…Results showed no significant differences between male and female woodlice: subjects of both sexes remained longer in the moist area than in the dry area and there was no statistical difference in the frequency of crossings. This indicated that both sexes of animals of this species equally preferred moist environments rather than dry ones, as previously suggested ( 18 , 36 - 38 ), which contrasts with previous studies that found some differences between sexes in exploratory behavior of rats ( 10 , 20 - 26 , 32 , 34 , 39 , 40 ).…”

“…In these studies, there seem to be no differences in exploratory behavior between females and males. In rats, however, females seem to explore novel environments in a somewhat different way than males (10,(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34).…”

Examining Anxiety and Risk-taking in Healthy Male and Female Wistar Rats using Spatial and Temporal Analysis of Elevated Plus Maze

“…Temporal analysis of time spent divided in smaller discrete time bins compared to the commonly used EPM measure of total time spent in open arms for the 5 minutes trial duration might provide a nuanced insight to sex-specific anxiety and risky preference of open arm. Our results indicate the possibility of high anxiety regulation in females and increase in risk-taking, our results corroborate with the rare reports of females exhibiting less anxious behaviour on the EPM (Pavlova et al 2020; Knight et al, 2021; Bonuti and Murato, 2022).…”

“…Although EPM is used for assessing anxiety and risk-taking in healthy male and female Wistar rats (Walf and Frye, 2007), inconsistencies in sex-specific anxiety and risk taking on Studies have also pointed out that temporal and spatial features tend to impact anxiety levels on EPM (Schneider, P., Ho, Y. J., Spanagel, R., & Pawlak, C. R., 2011). Therefore, we expect that detailed analysis of spatial and temporal aspects of EPM might improve our understanding of sex-differences in anxiety, for instance, modified EPM (elevated gradient of aversion, EGA) using shortened trial duration to 3 min indicated female rats might be less anxious compared to male counterparts (Bonuti, 2022). Donner and Lowry, 2013; Pavlova et.…”

Unraveling Sex Differences in Affect Processing: Unique Oscillatory Signaling Dynamics in the Infralimbic Cortex and Nucleus Accumbens Shell

“…The sex-specific changes in PAC in females are consistent with previous research showing the involvement of theta-gamma PAC on affect processing such as decreased theta-high gamma coupling in the NAc during appetitive conditioning ( 39 ) and enhanced theta-high gamma coupling in the basolateral amygdala during periods of fear ( 40 ). Likewise, female rats exhibit less anxiety/fear in the elevated gradient of aversion test ( 41 ), less contextual fear when freezing behavior is measured after foot shock ( 42 ), and greater aversion resistance in experiments using quinine-adulterated alcohol ( 43 , 44 ), although differential processing in the IL-NAcSh circuit of those types of aversive-related behaviors across sex remains to be examined.…”