Panic‐like responses of female Wistar rats confronted by Bothrops alternatus pit vipers, or exposure to acute hypoxia: Effect of oestrous cycle

Abstract

Anxiety‐related diseases are more than twice as common in women than in men, and in women, symptoms may be exacerbated during the late luteal phase of the menstrual cycle. Despite this, most research into the underlying mechanisms, which drives drug development, have been carried out using male animals. In an effort to redress this imbalance, we compared responses of male and female Wistar rats during exposure to two unconditioned threatening stimuli that evoke panic‐related defensive behaviours: confrontation with a predator (Bothrops alternatus) and acute exposure to hypoxia (7% O2). Threatened by venomous snake, male and female rats initially displayed defensive attention, risk assessment, and cautious interaction with the snake, progressing to defensive immobility to overt escape. Both males and females displayed higher levels of risk assessment but less interaction with the predator. They also spent more time in the burrow, displaying inhibitory avoidance, and more time engaged in defensive attention, and non‐oriented escape behaviour. In females, anxiety‐like behaviour was most pronounced in the oestrous and proestrus phases whereas panic‐like behaviour was more pronounced during the dioestrus phase, particularly during late dioestrus. Acute hypoxia evoked panic‐like behaviour (undirected jumping) in both sexes, but in females, responsiveness in late dioestrus was significantly greater than at other stages of the cycle. The results reveal that females respond in a qualitatively similar manner to males during exposure to naturally occurring threatening stimuli, but the responses of females is oestrous cycle dependent with a significant exacerbation of panic‐like behaviour in the late dioestrus phase.

Panicolytic‐like effects of environment enrichment on male mice threatened by Bothrops jararaca lancehead pit vipers

“…Rodrigues Ferreira-Sgobbi et al, 2022). This paradigm was etiologically and pharmacologically validated for both constrictor and venomous snakes.…”

CB1 receptor signalling mediates cannabidiol-induced panicolytic-like effects and defensive antinociception impairment in mice threatened by Bothrops jararaca lancehead pit vipers

“…This study used a prey-versus-snake paradigm, which considers the interaction between prey and a potential predator in the modified polygonal arena used for the snake panic tests (Ferreira-Sgobbi et al, 2022). The prey-versus-snake paradigm was ethologically and pharmacologically validated for constrictor (dos Anjos-Garcia and Coimbra, 2019;Guimarães-Costa et al, 2007;Lobão-Soares et al, 2008;Twardowschy et al, 2013;Uribe-Mariño et al, 2012) and for venomous snakes (Calvo et al, 2019a(Calvo et al, , 2019cCoimbra et al, 2017a).…”

Lateralization in Hemiparkinsonian Rats Is Affected by either Deep Brain Stimulation or Glutamatergic Neurotransmission in the Inferior Colliculus

“…The following behaviors were assessed: (1) the number of entries into and time spent on the open and closed arms; (2) the number of turns (90°; when approaching the center, the side chosen to change from open to closed arms, or vice versa) contraversive and ipsiversive to the lesion side; (3) the number of half rotations (180°) and rotations (360°) contraversive and ipsiversive to the lesion side (at both open and closed arms or at the center); and (4) the number of risk assessments contraversive and ipsiversive to the lesion side. Here, risk assessment was defined as aborted attempts to enter into open arms, which includes scanning, stretch/attend postures (when the rat stretches to its full length with its forepaws, keeps its hindpaws in the same place, and then turns back) and flat back approach (locomotion during which the animal stretches to its full length and cautiously moves forward; Griebel et al, 1997 ; Coimbra et al, 2017 ; Ferreira-Sgobbi et al, 2022 ). Each rat was tested only once on the EPM.…”