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Developmental Psychobiology Jul 2024Maternal deprivation, as a result of the artificial rearing (AR) paradigm, disturbs electrophysiological and histological characteristics of the peripheral sensory sural...
Maternal deprivation, as a result of the artificial rearing (AR) paradigm, disturbs electrophysiological and histological characteristics of the peripheral sensory sural (SU) nerve of infant and adult male rats. Such changes are prevented by providing tactile or social stimulation during isolation. AR also affects the female rat's brain and behavior; however, it is unknown whether this early adverse experience also alters their SU nerve development or if tactile stimulation might prevent these possible developmental effects. To assess these possibilities, the electrophysiological and histological characteristics of the SU nerve from adult diestrus AR female rats that: (i) received no tactile stimulation (AR group), (ii) received tactile stimulation in the anogenital and body area (AR-Tactile group), or (iii) were mother reared (MR group) were determined. We found that the amplitude, but not the area, of the evoked compound action potential response in SU nerves of AR rats was lower than those of SU nerves of MR female rats. Tactile stimulation prevented these effects. Additionally, we found a reduction in the outer diameter and myelin thickness of axons, as well as a large proportion of axons with low myelin thickness in nerves of AR rats compared to the nerves of the MR and AR-Tactile groups of rats; however, tactile stimulation only partially prevented these effects. Our data indicate that maternal deprivation disturbs the development of sensory SU nerves in female rats, whereas tactile stimulation partially prevents the changes generated by AR. Considering that our previous studies have shown more severe effects of AR on male SU nerve development, we suggest that sex-associated factors may be involved in these processes.
Topics: Animals; Female; Rats; Sural Nerve; Maternal Deprivation; Touch; Physical Stimulation; Rats, Wistar; Axons; Action Potentials; Myelin Sheath
PubMed: 38739111
DOI: 10.1002/dev.22486 -
Australian Veterinary Journal May 2024A number of methods are currently used to predict the optimal date of insemination of the breeding bitch, particularly with the use of frozen-thawed canine semen which... (Review)
Review
A number of methods are currently used to predict the optimal date of insemination of the breeding bitch, particularly with the use of frozen-thawed canine semen which has a far shorter lifespan than fresh semen. Aside from confirming cytological oestrus, vaginal cytology is of no assistance in predicting the most fertile day(s) in a bitch; however, a neglected avenue of research suggests that vaginal cytology may be of great importance in confirming the days of optimal fertility retrospectively. Similarly, vaginoscopy provides clues as to the stage of a bitch's cycle but is inadequate as a sole determinant of her most fertile days. Nevertheless, vaginoscopy is useful to identify very late oestrus and the onset of dioestrus, as well as Stage I of labour (cervical dilatation). Due to variations in the rate at which circulating progesterone concentrations rise in individual bitches, the reliability of circulating progesterone concentrations for determining the optimal day(s) of insemination with frozen-thawed semen decreases as values rise. Moreover, progesterone assay results can vary widely due to extrinsic factors such as the time of blood sampling, sample storage conditions and the assay employed. Finally, this review investigates evidence surrounding various insemination routes and suggests that well-performed vaginal insemination, even with frozen-thawed semen, may be an acceptable approach for cases where transcervical insemination is impractical.
PubMed: 38733177
DOI: 10.1111/avj.13336 -
Biology of Reproduction Jun 2024Uterine muscle contractility is essential for reproductive processes including sperm and embryo transport, and during the uterine cycle to remove menstrual effluent....
Uterine muscle contractility is essential for reproductive processes including sperm and embryo transport, and during the uterine cycle to remove menstrual effluent. Even still, uterine contractions have primarily been studied in the context of preterm labor. This is partly due to a lack of methods for studying the uterine muscle contractility in the intact organ. Here, we describe an imaging-based method to evaluate mouse uterine contractility of both the longitudinal and circular muscles in the cycling stages and in early pregnancy. By transforming the image-based data into three-dimensional spatiotemporal contractility maps, we calculate waveform characteristics of muscle contractions, including amplitude, frequency, wavelength, and velocity. We report that the native organ is highly contractile during the progesterone-dominant diestrus stage of the cycle when compared to the estrogen-dominant proestrus and estrus stages. We also observed that during the first phase of uterine embryo movement when clustered embryos move toward the middle of the uterine horn, contractions are dynamic and non-uniform between different segments of the uterine horn. In the second phase of embryo movement, contractions are more uniform and rhythmic throughout the uterine horn. Finally, in Lpar3-/- uteri, which display faster embryo movement, we observe global and regional increases in contractility. Our method provides a means to understand the wave characteristics of uterine smooth muscle in response to modulators and in genetic mutants. Better understanding uterine contractility in the early pregnancy stages is critical for the advancement of artificial reproductive technologies and a possibility of modulating embryo movement during clinical embryo transfers.
Topics: Female; Animals; Uterine Contraction; Pregnancy; Mice; Uterus; Estrous Cycle
PubMed: 38713674
DOI: 10.1093/biolre/ioae071 -
Behavioral Neuroscience Apr 2024Rodent behavioral studies have largely focused on male animals, which has limited the generalizability and conclusions of neuroscience research. Working with humans and...
Rodent behavioral studies have largely focused on male animals, which has limited the generalizability and conclusions of neuroscience research. Working with humans and rodents, we studied sex effects during interval timing that requires participants to estimate an interval of several seconds by making motor responses. Interval timing requires attention to the passage of time and working memory for temporal rules. We found no differences between human females and males in interval timing response times (timing accuracy) or the coefficient of variance of response times (timing precision). Consistent with prior work, we also found no differences between female and male rodents in timing accuracy or precision. In female rodents, there was no difference in interval timing between estrus and diestrus cycle stages. Because dopamine powerfully affects interval timing, we also examined sex differences with drugs targeting dopaminergic receptors. In both female and male rodents, interval timing was delayed after administration of sulpiride (D2-receptor antagonist), quinpirole (D2-receptor agonist), and SCH-23390 (D1-receptor antagonist). By contrast, after administration of SKF-81297 (D1-receptor agonist), interval timing shifted earlier only in male rodents. These data illuminate sex similarities and differences in interval timing. Our results have relevance for rodent models of both cognitive function and brain disease by increasing representation in behavioral neuroscience. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
Topics: Female; Male; Animals; Time Perception; Humans; Sex Characteristics; Dopamine; Rats; Receptors, Dopamine D2; Sulpiride; Quinpirole; Dopamine Agonists; Dopamine Antagonists; Adult; Reaction Time; Benzazepines; Young Adult; Receptors, Dopamine D1; Memory, Short-Term
PubMed: 38661668
DOI: 10.1037/bne0000577 -
Progress in Neuro-psychopharmacology &... Jul 2024Alcohol use disorder is a substantial social and economic burden. During the last years, the number of women with drinking problems has been increasing, and one main...
Alcohol use disorder is a substantial social and economic burden. During the last years, the number of women with drinking problems has been increasing, and one main concern is that they are particularly more vulnerable to negative consequences of alcohol. However, little is known about female-specific response patterns for alcohol, and potential underlying differences in brain mechanisms, including for compulsion-like alcohol drinking (when intake persists despite adverse consequences). We used lickometry to assess behavioral microstructure in adult Wistar male and female rats (n = 28-30) during alcohol-only drinking or moderate- or higher-challenge alcohol compulsion (10 or 60 mg/l quinine in alcohol, respectively). Estrous stages were determined and related to drinking levels and patterns of responding to alcohol, as was ovariectomy. Our findings showed that females (where we didn't determine estrus stage) had similar total licks in a session as males, but significantly longer licking bouts under alcohol-only and moderate-challenge, suggesting greater persistence. Further, greater intake under alcohol-only and moderate-challenge was related to faster licking in males, while female consumption was not related to licking speed. Thus, females could have increased persistence without greater vigor, unlike males. However, under higher-challenge, faster licking did predict higher intake in females, similar to males. To better understand female higher-challenge responding, we examined drinking in relation to phases of the estrous cycle. Higher-challenge had longer bouts only in late diestrus. In addition, ovariectomy led to longer bouts only under higher-challenge, suggesting that conditions with reduced hormone levels could increase female persistence for alcohol under higher-challenge. However, ovariectomy also reduced alcohol-only and moderate-challenge drinking but did not reduce bout length. Thus, intake level and response strategy could be regulated somewhat differently by ovarian hormones. Finally, moderate-challenge licking speed was less variable during early diestrus, and we previously showed more stereotyped responding specifically under moderate-challenge in males. By combining behavioral microstructure and sex- and estrus-related changes in drinking patterns, our results suggest that females have greater persistence for alcohol under lower-challenge drinking, while late diestrus and ovariectomy unmasked greater persistence under higher-challenge. Together, our novel insights could help develop more effective and personalized treatments for problematic alcohol use.
Topics: Animals; Female; Male; Rats; Rats, Wistar; Alcohol Drinking; Sex Characteristics; Ethanol; Ovariectomy; Estrous Cycle; Compulsive Behavior; Quinine
PubMed: 38641236
DOI: 10.1016/j.pnpbp.2024.111008 -
Behavioural Processes Apr 2024Detection dogs are frequently tested for their ability to detect a variety of targets. It is crucial to comprehend the processes for odour learning and the consequences...
Detection dogs are frequently tested for their ability to detect a variety of targets. It is crucial to comprehend the processes for odour learning and the consequences of training on an expanding set of target scents on performance. To properly evaluate their ability to identify the target, the only true measure is the dogs' initial response to novel sources, since this excludes learning effects. In this study, we evaluated the individual learning processes of three detection dogs that were pre-trained to differentially respond to a faecal sample of a mare in oestrus (S+) and a faecal sample of the same mare in di-oestrus (S-). After reaching criterion during a test with known training samples, the dogs were tested for generalization to a novel source. Average responses to S+ and S- were calculated as a function of presentation sequence, and Signal Detection Theory was used to further analyse characteristic differences in learning. The results of this study suggest that the ability of individual scent detection dogs to learn within an olfactory discrimination test varies considerably. The information obtained in this study could be helpful for mitigation training. We show that through careful monitoring of individual learning processes, the strategy each dog followed becomes apparent: especially the observations on the dogs' responses to first encounters with novel sample sources. This provides us with more detailed information than the more traditional sensitivity and specificity measures and allows us to better predict the dog's capabilities.
Topics: Animals; Dogs; Female; Smell; Odorants; Discrimination Learning; Olfactory Perception; Behavior, Animal; Learning; Male
PubMed: 38636131
DOI: 10.1016/j.beproc.2024.105030 -
Heliyon Apr 2024Social isolation can cause serious problem in performance of individuals in community. As gender differences may cause variation results in the severity of depressive...
The role of gender differences in the outcome of juvenile social isolation: Emphasis on changes in behavioral, biochemical and expression of nitric oxide synthase genes alteration.
Social isolation can cause serious problem in performance of individuals in community. As gender differences may cause variation results in the severity of depressive behavior and response of patients to therapy, the impact of gender and the interaction of the level of endocrine secretion in depression were investigated in this study. Wistar rats of both sexes were subjected to post-weaning social isolation (PWSI) conditions and, together with the control group, experienced several behavioral tests including open-field Test (OFT), elevated plus maze (EPM), force swimming test (FST), splash test and novel object recognition test (NOR). Hippocampal tissue was isolated to measure biochemical factors such as nitric oxide level, FRAP amount, MDA level. In addition, real-time-PCR test was used to quantify the genes expression level of inducible nitric oxide synthase (iNOS) and neuronal nitric oxide synthase (nNOS). On the other hand, sexual hormone levels in blood were measured. Both cognitive and behavioral f unctions were declined as the result of PWSI induction in male and diestrus female rats. The consequent surge of estradiol during estrous phase seems to suppress the accumulation of reactive oxygen species (ROS), and modulate iNOS and nNOS expression. In conclusion, while the pattern of PWSI in surge cellular antioxidants, raising cellular ROS level is gender-specific, this alleviation was in relation with the drop of estradiol and unrelated with testosterone level.
PubMed: 38617928
DOI: 10.1016/j.heliyon.2024.e28964 -
BioRxiv : the Preprint Server For... Apr 2024Food intake varies across the stages of a rat's estrous cycle. It is reasonable to hypothesize that this cyclic fluctuation in consumption reflects an impact of hormones...
UNLABELLED
Food intake varies across the stages of a rat's estrous cycle. It is reasonable to hypothesize that this cyclic fluctuation in consumption reflects an impact of hormones on taste palatability/preference, but evidence for this hypothesis has been mixed, and critical within-subject experiments in which rats sample multiple tastes during each of the four main estrous phases (metestrus, diestrus, proestrus, and estrus) have been scarce. Here, we assayed licking for pleasant (sucrose, NaCl, saccharin) and aversive (quinine-HCl, citric acid) tastes each day for 5-10 days while tracking rats' estrous cycles through vaginal cytology. Initial analyses confirmed the previously-described increased consumption of pleasant stimuli 24-48 hours following the time of high estradiol. A closer look, however, revealed this effect to reflect a general magnification of palatability-higher than normal preferences for pleasant tastes and lower than normal preferences for aversive tastes-during metestrus. We hypothesized that this phenomenon might be related to estradiol processing in the lateral hypothalamus (LH), and tested this hypothesis by inhibiting LH estrogen receptor activity with ICI during tasting. Control infusions replicated the metestrus magnification of palatability pattern; ICI infusions blocked this effect as predicted, but failed to render preferences "cycle free," instead delaying the palatability magnification until diestrus. Clearly, estrous phase mediates details of taste palatability in a manner involving hypothalamic actions of estradiol; further work will be needed to explain the lack of a flat response across the cycle with hypothalamic estradiol binding inhibited, a result which perhaps suggests dynamic interplay between brain regions or hormones.
SIGNIFICANCE STATEMENT
Consummatory behaviors are impacted by many variables, including naturally circulating hormones. While it is clear that consumption is particularly high during the stages following the high-estradiol stage of the rodent's estrous (and human menstrual) cycle, it is as of yet unclear whether this phenomenon reflects cycle stage-specific palatability (i.e., whether pleasant tastes are particularly delicious, and aversive tastes particularly disgusting, at particular phases). Here we show that palatability is indeed modulated by estrous phase, and that this effect is governed, at least in part, by the action of estradiol within the lateral hypothalamus. These findings shed light on the mechanisms underlying the adverse impact on human welfare due to irregularities observed across the otherwise cyclic menstrual process.
PubMed: 38617267
DOI: 10.1101/2024.04.01.587593 -
Reproduction in Domestic Animals =... Apr 2024Estrus identification is one of the common issues in buffaloes because of their short estrus duration and silent estrus problem. Hence, specific biomarkers facilitating...
Estrus identification is one of the common issues in buffaloes because of their short estrus duration and silent estrus problem. Hence, specific biomarkers facilitating in identifying the estrus stage would be helpful to buffalo farmers and researchers. In our previous studies, taurine, a non-protein amino acid that helps in the secretion of reproductive hormones such as GnRH, was found to be associated with postpartum anestrus in buffaloes. Therefore, the present study was conducted to explore the level of taurine in serum during different stages of the oestrous cycle in healthy cyclic buffaloes. Blood samples were collected from healthy cyclic buffaloes (n = 4), and taurine was estimated at the estrus (0th day), proestrus (-2nd day), metestrus (3rd day) and diestrus (+10th day) stages using TLC method. The days of the oestrous cycle were determined by ultrasonography and observation of behavioural signs by trained professionals. The results revealed that taurine was consistently present in the serum. However, the highest concentration of taurine was observed at the proestrus (0.20 ± 0.03 mg/mL) stage, which was greater (p < .05) than metestrus (0.10 ± 0.05 mg/mL) and diestrus (0.13 ± 0.03 mg/mL) stages, but comparable with the estrus stage. These results were also validated in the simulated population datasets of population size 6 to 10,000. Further, ROC curve analysis for the large simulated population indicated the efficiency of taurine to distinguish proestrus from metestrus and diestrus stages at a lower cutoff value of <0.1643 mg/mL with 60% sensitivity and specificity. Therefore, the present study concludes that serum taurine concentration could help in detecting proestrus stage of buffalo estrous cycle.
Topics: Female; Animals; Buffaloes; Taurine; Estrous Cycle; Estrus; Diestrus; Proestrus; Bison
PubMed: 38595035
DOI: 10.1111/rda.14560 -
The Journal of Endocrinology Jun 2024The mouse estrous cycle is divided into four stages: proestrus (P), estrus (E), metestrus (M), and diestrus (D). The estrous cycle affects reproductive hormone levels in...
The mouse estrous cycle is divided into four stages: proestrus (P), estrus (E), metestrus (M), and diestrus (D). The estrous cycle affects reproductive hormone levels in a wide variety of tissues. Therefore, to obtain reliable results from female mice, it is important to know the estrous cycle stage during sampling. The stage can be analyzed from a vaginal smear under a microscope. However, it is time-consuming, and the results vary between evaluators. Here, we present an accurate and reproducible method for staging the mouse estrous cycle in digital whole-slide images (WSIs) of vaginal smears. We developed a model using a deep convolutional neural network (CNN) in a cloud-based platform, Aiforia Create. The CNN was trained by supervised pixel-level multiclass semantic segmentation of image features from 171 hematoxylin-stained samples. The model was validated by comparing the results obtained by CNN with those of four independent researchers. The validation data included three separate studies comprising altogether 148 slides. The total agreement attested by the Fleiss kappa value between the validators and the CNN was excellent (0.75), and when D, E, and P were analyzed separately, the kappa values were 0.89, 0.79, and 0.74, respectively. The M stage is short and not well defined by the researchers. Thus, identification of the M stage by the CNN was challenging due to the lack of proper ground truth, and the kappa value was 0.26. We conclude that our model is reliable and effective for classifying the estrous cycle stages in female mice.
Topics: Animals; Female; Estrous Cycle; Deep Learning; Mice; Vaginal Smears; Neural Networks, Computer; Image Processing, Computer-Assisted; Reproducibility of Results
PubMed: 38593833
DOI: 10.1530/JOE-23-0204