The use of infrared technology as a novel approach for studies with female laboratory animals

Ratko, Martina; Habek, Nikola; Kordić, Milan; Dugandžić, Aleksandra

doi:10.3325/cmj.2020.61.346

Cited by 5 publications

(6 citation statements)

References 27 publications

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“…These include using non-stained smear material ( 27 , 40 ), modifications to staining methods ( 41 ) and application of deep learning technology for classification of smears ( 42 ). Alternatives to vaginal cytology have been proposed based on gross examination of the vaginal opening ( 43 ), changes in skin temperature due to activation of brown adipose tissue ( 44 ) and variations in vaginal wall impedence ( 45 ). To date, none of the latter methods has been widely adopted and vaginal cytology remains the gold standard for assessing estrous cycle stage.…”

Section: Introductionmentioning

confidence: 99%

Effect of Estrous Cycle on Behavior of Females in Rodent Tests of Anxiety

2021

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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.

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Section: Introductionmentioning

confidence: 99%

Effect of Estrous Cycle on Behavior of Females in Rodent Tests of Anxiety

2021

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“…BAT thermogenesis activation will naturally transfer heat energy throughout the vascular system and cause changes in the body surface temperature. Ratko et al [38] have examined the correlation between the activity of BAT and skin temperature of mice using infrared thermography. Similarly, in this study, we observed the activity of BAT by infrared thermography.…”

Section: Discussionmentioning

confidence: 99%

Effect of Electroacupuncture Stimulation on Brown Adipose Tissue Thermogenesis

Li,

Wu,

Tian

et al. 2024

J Acupunct Meridian Stud

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Background: Brown adipose tissue (BAT) is a unique thermogenic tissue in mammals mediated by uncoupling protein 1 (UCP1). The energy generated by glucose and triglyceride metabolism is released and transmitted throughout the body as heat. Understanding the factors influencing BAT function is crucial to determine its metabolic significance and effects on overall health. Although studies have shown that electroacupuncture (EA) at specific acupoints (e.g., ST36) can stimulate BAT, its effects at other acupoints are not well understood. Further research is needed to investigate the potential effects of EA at these acupoints and their association with BAT activation. Objectives: This study aimed to investigate the effects of EA at the GV20 and EX-HN3 acupoints. Specifically, the effects of EA on BAT thermogenesis were analyzed by infrared thermography, western blotting, and real-time polymerase chain reaction (PCR). Methods: A total of 12 C57BL/6J mice were randomly divided into the EA and control groups. The EA group received EA at GV20 and EX-HN3 for 20 min once daily for 14 days. The control group underwent the same procedure but without EA. The core body temperature was monitored. Infrared thermal images of the back of each mouse in both groups were captured. BAT samples were collected after euthanasia to analyze UCP1 protein and UCP1 mRNA. Results:The average skin temperature in the scapular region of the EA group was increased by 1.1℃ compared with that of the C group (p < 0.05). Additionally, the average temperature along the governor vessel in the EA group was increased by 1.6℃ (p = 0.045). EA significantly increased the expression of UCP1 protein (p = 0.001) and UCP1 mRNA (p = 0.002) in BAT, suggesting a potential link between EA and BAT thermogenesis. Conclusion: EA induced BAT thermogenesis, suggesting GV20 and EX-HN3 as potential acupoints for BAT stimulation. The experimental results also highlighted unique meridian characteristics as demonstrated by elevated skin temperature along the governor vessel in mice.

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“…IRT has been used in larger animals and can be affected by other variables including room temperature, pain, and inflammation as well as body surface region tested [ 11 ]. Few studies have examined changes in surface temperature in mice with one study demonstrating lower temperatures during diestrus [ 38 ]. In sheep, one study recorded lower temperatures during diestrus as well using IRT [ 5 ].…”

Section: Discussionmentioning

confidence: 99%

“…Additional studies in larger cohorts may be needed to determine the sensitivity and specificity of this method as a noninvasive tool for prediction of estrus cycle stage in mice. In this study, we did not do standard interval assessment of estrus cycle stage or determine temperature at time of ovulation [ 38 ]. Nonetheless, like other reports, we did find that temperature changed during the estrus cycle in a small cohort of animals.…”

Section: Discussionmentioning

confidence: 99%

The effect of sex and estrus cycle stage on optogenetic spreading depression induced migraine-like pain phenotypes

Harriott,

Waruinge,

Appiah-Danquah

et al. 2023

J Headache Pain

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Background Migraine is more prevalent in females, raising the possibility that sex and gonadal hormones modulate migraine. We recently demonstrated that minimally invasive optogenetic spreading depolarization (opto-SD) elicits robust periorbital allodynia. The objective of this study was to test the hypothesis that opto-SD induced migraine-like pain behavior is worse in females and varies during the estrus cycle. Methods Single or repeated opto-SDs were induced in male and female adult Thy1-ChR2-YFP transgenic mice. Von Frey monofilaments were used to test periorbital mechanical allodynia. Mouse grimace was also examined under increasing light intensity to quantify spontaneous discomfort and light-aversive behavior. Vaginal smears were obtained for estrus cycle staging at the end of behavioral testing. Results A multi-variable regression analysis was performed using a male and female cohort to test the effect of independent variables on periorbital allodynia. Opto-SD predicted lower periorbital thresholds as compared with sham stimulation (p < 0.0001). Additionally, female sex predicted lower periorbital thresholds compared with males (p = 0.011). There were significant interactions between opto-SD and time (interaction p = 0.030) as animals tended to recover from opto-SD allodynia over time, and between sex and time (p = 0.020) as females tended to take longer to recover. Proestrus, estrus (PE) and metestrus, diestrus (MD) stages were combined to represent high versus low circulating estradiol relative to progesterone, respectively. Multi-variable regression revealed an effect of estrus cycle (p = 0.015) on periorbital thresholds. In the sham group, PE had lower thresholds than MD. However, there was no interaction between opto-SD and the estrus cycle (p = 0.364). Grimace scores were also examined at incremental light intensities. There was an effect of opto-SD (p < 0.0001), light intensity (p = 0.001) and estrus cycle (p = 0.024) on grimace without interaction among them (three-way ANOVA). Conclusions Female sex and estrus stages with high circulating estradiol relative to progesterone lower trigeminal pain thresholds and augment photosensitivity. In females, opto-SD increased pain behavior and photosensitivity irrespective of the estrus stage. Graphical Abstract

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The use of infrared technology as a novel approach for studies with female laboratory animals

Cited by 5 publications

References 27 publications

Effect of Estrous Cycle on Behavior of Females in Rodent Tests of Anxiety

Effect of Estrous Cycle on Behavior of Females in Rodent Tests of Anxiety

Effect of Electroacupuncture Stimulation on Brown Adipose Tissue Thermogenesis

The effect of sex and estrus cycle stage on optogenetic spreading depression induced migraine-like pain phenotypes

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