--- title: How does the female reproductive cycle affect anxiety in rodent studies? description: Female rodents show more anxiety responses during the late phase of their reproductive cycle, similar to the premenstrual phase in women. This is animal resea url: https://niyora.com/research/papers/effect-of-estrous-cycle-on-behavior-of-females-in-rodent-tests-of-anxiety-2021/ --- - [Niyora](https://niyora.com/) - [Research](https://niyora.com/research/) - [Library](https://niyora.com/research/library/) - How does the female reproductive cycle affect anxiety in rodent studies? Interview study, 2021 # How does the female reproductive cycle affect anxiety in rodent studies? Female rodents show more anxiety responses during the late phase of their reproductive cycle, similar to the premenstrual phase in women. This is animal research, not human research, so findings may not directly apply to women. Early or limited evidence Female rodents across various anxiety and fear studies ## What they did Researchers reviewed anxiety and fear tests in female rodents across multiple studies, examining how reproductive cycle phase affects behavior and comparing females to males. ## What they found Female rodents displayed more anxiety responses during the late phase of their reproductive cycle, similar to the premenstrual phase in women. Tests based on direct threats were affected by cycle phase. Tests based on learned fear showed less impact from cycle phase. The same behavior might be caused by different brain mechanisms in females versus males. ## What it means for you This is animal research, not human research, so findings may not apply directly to women with PMS. It does show that female rodents have more anxiety at certain cycle phases, similar to premenstrual anxiety in some women. The research highlights a gap: most drug testing for anxiety has used only male animals, so we may not fully understand how treatments affect women. 4 days rodent reproductive cycle length ## About the study Original title Effect of Estrous Cycle on Behavior of Females in Rodent Tests of Anxiety Authors Lovick TA, Zangrossi H Jr Journal Frontiers in psychiatry Year 2021 Study design Interview study Open access Yes Read the paper [doi.org/10.3389/fpsyt.2021.711065](https://doi.org/10.3389/fpsyt.2021.711065) Original abstract Anxiety disorders are more prevalent in women than in men. In women the menstrual cycle introduces another variable; indeed, some conditions e.g., premenstrual syndrome, are menstrual cycle specific. Animal models of fear and anxiety, which form the basis for research into drug treatments, have been developed almost exclusively, using males. There remains a paucity of work using females and the available literature presents a confusing picture. One confound is the estrous cycle in females, which some authors consider, but many do not. Importantly, there are no accepted standardized criteria for defining cycle phase, which is important given the rapidly changing hormonal profile during the 4-day cycle of rodents. Moreover, since many behavioral tests that involve a learning component or that consider extinction of a previously acquired association require several days to complete; the outcome may depend on the phase of the cycle on the days of training as well as on test days. In this article we consider responsiveness of females compared to males in a number of commonly used behavioral tests of anxiety and fear that were developed in male rodents. We conclude that females perform in a qualitatively similar manner to males in most tests although there may be sex and strain differences in sensitivity. Tests based on unconditioned threatening stimuli are significantly influenced by estrous cycle phase with animals displaying increased responsiveness in the late diestrus phase of the cycle (similar to the premenstrual phase in women). Tests that utilize conditioned fear paradigms, which involve a learning component appear to be less impacted by the estrous cycle although sex and cycle-related differences in responding can still be detected. Ethologically-relevant tests appear to have more translational value in females. However, even when sex differences in behavior are not detected, the same outward behavioral response may be mediated by different brain mechanisms. In order to progress basic research in the field of female psychiatry and psychopharmacology, there is a pressing need to validate and standardize experimental protocols for using female animal models of anxiety-related states. Reproduced under CC-BY. ## Topics [Premenstrual syndrome (PMS)](https://niyora.com/research/topics/condition-pms/)[Anxiety and tension](https://niyora.com/research/topics/symptom-anxiety/)[Anxiety disorders and OCD](https://niyora.com/research/topics/comorbidity-anxiety-disorders/) Research tells you what helps on average. Niyora helps on the day it hits. Calm down, see it another way, and decide what to say, with a PMS and PMDD app built by a doctor. ## Related studies Review, 2024 What is premenstrual exacerbation and how does it affect different psychiatric illnesses? Systematic review, 2022 Do mental health disorders get worse during the menstrual cycle? Non-randomised trial, 2008 Can the Sheehan Disability Scale measure whether treatments work? Randomised trial, 1999 Do SSRIs reduce premenstrual dysphoria symptoms? Cohort study, 1993 How common are premenstrual and menstrual symptoms in women? Study, 2026 Do anxiety and depression get worse before your period if you already have a mental health condition? Ask AI about this page Copy prompt ChatGPT ↗ Claude ↗ Perplexity ↗ Google AI Mode ↗ Grok ↗