Juvenile Females Research Articles

Sex and Age-related Parasitism of <i>Clarias gariepinus</i> in earthen ponds in African Regional Aquaculture Centre, Aluu, Rivers State, Nigeria

This study aimed at investigating the sex and age-related parasitic burden of Clarias gariepinus cultured in earthen ponds. Eighty–five (85) fish samples were selected randomly for analyses from three earthen ponds. Sexing was done by the observation of the urinogenital papillae. For parasitological analysis, skin and gill scrapes were taken for external parasites while the stomach and intestines were slit open, rinsed and observed for helminthic worms. Parasites identified included; Chilodonella sp. (0.3%), Ichthyophthirius sp. (41.1%), Trichodina sp. (55%), Icthyobodo sp., (1.0%) and Gyrodactylus sp. (2.4%). From the study 31 out of 56 males and 20 out of 27 females were infected with parasites. Prevalence of infection in males and females were 55.36% and 74.07% respectively. Mean intensity of parasites was also higher for females (150.75) than for males (62.68) Chi square analysis however, revealed no significant effect (p<0.05) of parasitism on gender. It was further observed that juvenile males and early adult females respectively, had more parasites with 55.3 and 92.4 parasite mean intensities. Among age groups, the mid juveniles (25-99g) (19%), late juveniles (100-299g) (65%) and early adults (300-500g) (14%) were most infected, although there was no significant effect (p<0.05). Sex-related prevalence could be based on hormonal changes and reproduction in females, and competitive search for mates by males. Age-related infection was predicated upon active feeding habits reported among fish of these ages It is therefore recommended that routine health checks be carried out for pond cultured fish. Furthermore, that older fish be sorted and kept together, as they would have stronger immunity than younger fish.
 Keywords; Zoonoses, fish infection, late juveniles, earthen pond, Clarias gariepinus, sex, age

Social Tolerance in Chimpanzees Depends on Group Composition: A Longitudinal Study Across Four Communities

Social tolerance in primates has commonly been treated as a stable, species-specific characteristic. Recent research, however, has questioned this position and emphasized the importance of considering intra-species variation in social tolerance. Here, we investigate the temporal stability of social tolerance in chimpanzees using the commonly employed measure of cofeeding tolerance; our results present the first multi-group, longitudinal, experimental assay of cofeeding tolerance in chimpanzees using quantitative methods. Cofeeding tolerance is measured in four groups of neighboring sanctuary-housed chimpanzees over the course of eight years. We pair these experimental data with accessory data on the demographic compositions of the groups to study factors that may influence cofeeding tolerance. We find appreciable levels of variation across both groups and years. We show that most of this variation can be explained by specific demographic variables, such as the number of young infants and the number of juvenile and adolescent females present within a group in a given year. These results imply that social tolerance is a ‘responding trait’ of chimpanzee sociality, reflecting individual- and group-level responses to social and demographic changes. To fully describe intra-species ranges of social tolerance, future research should consider the extent of variation both between groups as well as within groups over time.

Maternal separation induces changes in TREK-1 and 5HT1A expression in brain areas involved in the stress response in a sex-dependent way

Depression is a prevalent disease in modern society, and has been linked to stressful events at early ages. Women are more susceptible to depression, and the neural basis for this are still under investigation. Serotonin is known to be involved in depression, and a decrease in 5HT1A expression is observed on temporal and cortical areas in both men and women with depression. As knockout animals for TREK-1 are resilient to depression, this channel has emerged as a new potential pharmacological target for depression treatment. In this study, maternal separation (MS) was used to emulate early-life stress, and evaluate behaviour, as well as TREK-1 and 5HT1A expression in the brain using immunohistochemistry. In juvenile females, 5HT1A reduction coupled to increased TREK-1 in the dentate gyrus (DG) was associated with behavioural despair, as well as increased TREK-1 expression in basolateral amygdala (BLA) and prelimbic cortex (PL). In juvenile males, MS induced an increase in 5HT1A in the BLA, and in TREK-1 in the PL, while no behavioural despair was observed. Anhedonia and anxiety-like behaviour were not induced by MS. We conclude stress-induced increase in TREK-1 in PL and GD is associated to depression, while 5HT1A changes coupled to TREK-1 changes may be necessary to induce depression, with females being more vulnerable to MS effects than males. Thus, TREK-1 and 5HT1A may be potential pharmacological targets for antidepressants development.

When survival matters: is decreasing survival underlying the decline of common pochard in western Europe?

In western Europe, common pochard populations have experienced a sharp decline over the last two decades, together with an increasing proportion of males. Both of these changes were suggested to result from decreasing survival of nesting females (i.e. survival of adult females) owing to increasing predation pressure. To test this hypothesis, we used capture–mark–recapture/recovery data of common pochard ringed during autumn–winter (October–February) in three countries of western Europe (Switzerland, United Kingdom and France). We found no evidence for decreasing survival of individuals ringed in the United Kingdom or in Switzerland over the long term (1977–2011). In France, adult males and juvenile females experienced significant decreasing survival over a shorter interval (2004–2017). Overall, females displayed lower survival than males, although this was only weakly supported by the French dataset. In contrast, only sex differences and no age differences in survival rates were recorded in the UK and Switzerland (females 0.67 ± 0.03 and 0.69 ± 0.03; males: 0.81 ± 0.01 and 0.75 ± 0.01, respectively), while both age and sex differences were recorded for France (adult females 0.62 ± 0.07, adult males 0.66 ± 0.07, juvenile females 0.49 ± 0.08, juvenile males 0.54 ± 0.08). Therefore, decreasing survival of adult females was unlikely the underlying cause of the decline of common pochard populations in western Europe. Using an age‐structured two‐sex matrix population model, we show that when adult males experience higher survival than adult females (as it is the case for common pochards), decreasing survival of nests and/or juveniles can trigger decreasing population size and increasing proportions of males at the same time.

Survival and Recruitment among Non-Migratory Canada Geese (Branta canadensis): Influence of Gosling Sex, Hatching Date, Mass at Fledging, and Family Type

Among some Arctic-nesting geese, mass at fledging impacts first-year survival and recruitment into the breeding population, but this might not be true for temperate-nesting geese. For 25 years, we examined what variables impacted survival and recruitment of 731 Canada Geese (Branta canadensis) fledglings raised in Connecticut, USA by tracking individually marked birds throughout their lives. At fledging, the number of females (391) were similar to males (340), but by the end of the first year of life, females (247) outnumbered males (187). This can be explained due to the apparent survival rates for juvenile females (0.63) being higher than for males (0.55). Dispersal rate from natal areas were similar for males and females during the first year of life and cannot account for why females outnumbered males after one year of life. Apparent survival rates of female fledglings to the end of the second year was 0.48. For the 247 females still alive at the end of their first year of life, 190 were still alive at the end of their second year of life, yielding a 0.77 apparent survival rates during their second year of life. Sex was the only variable that explained the survival of fledglings until the end of their first year of life. The probability of females surviving the second year of life was not influenced by hatching date, fledging age, fledging mass, or family type. Heavier females at fledging were more likely to be recruited into the breeding population than lighter ones. Our results indicate that while an inability to acquire sufficient mass as a gosling does not affect survival, it impacts the ability to be recruited.

Proteomic and mitochondrial adaptations to early-life stress are distinct in juveniles and adults

Exposure to early-life stress (ELS) increases risk for poor mental and physical health outcomes that emerge at different stages across the lifespan. Yet, how age interacts with ELS to impact the expression of specific phenotypes remains largely unknown. An established limited-bedding paradigm was used to induce ELS in mouse pups over the early postnatal period. Initial analyses focused on the hippocampus, based on documented sensitivity to ELS in humans and various animal models, and the large body of data reporting anatomical and physiological outcomes in this structure using this ELS paradigm. An unbiased discovery proteomics approach revealed distinct adaptations in the non-nuclear hippocampal proteome in male versus female offspring at two distinct developmental stages: juvenile and adult. Gene ontology and KEGG pathway analyses revealed significant enrichment in proteins associated with mitochondria and the oxidative phosphorylation (OXPHOS) pathway in response to ELS in female hippocampus only. To determine whether the protein adaptations to ELS reflected altered function, mitochondrial respiration (driven through complexes II-IV) and complex I activity were measured in isolated hippocampal mitochondria using a Seahorse X96 Flux analyzer and immunocapture ELISA, respectively. ELS had no effect on basal respiration in either sex at either age. In contrast, ELS increased OXPHOS capacity in juvenile males and females, and reduced OXPHOS capacity in adult females but not adult males. A similar pattern of ELS-induced changes was observed for complex I activity. These data suggest that initial adaptations in juvenile hippocampus due to ELS were not sustained in adults. Mitochondrial adaptations to ELS were also exhibited peripherally by liver. Overall, the temporal distinctions in mitochondrial responses to ELS show that ELS-generated adaptations and outcomes are complex over the lifespan. This may contribute to differences in the timing of appearance of mental and physical disturbances, as well as potential sex differences that influence only select outcomes.

Sex differences in prefrontal cortex microglia morphology: Impact of a two-hit model of adversity throughout development

Neuroimmune mechanisms play critical roles in brain development and can be impacted by early life adversity. Microglia are the resident immune cells in the brain, with both sex-specific and region-specific developmental profiles. Since early life adversity is associated with several neuropsychiatric disorders with developmental pathogeneses, here we investigated the degree to which maternal separation (MS) impacted microglia over development. Microglia are dynamic cells that alter their morphology in accordance with their functions and in response to stressors. While males and females reportedly display different microglial morphology in several brain regions over development and following immune and psychological challenges, little is known about such differences in the prefrontal cortex (PFC), which regulates several early life adversity-attributable disorders. Additionally, little is known about the potential for early life adversity to prime microglia for later immune challenges. In the current study, male and female rats were exposed to MS followed by lipopolysaccharide administration in juvenility or adolescence. The prelimbic and infralimbic PFC were then separately analyzed for microglial density and morphology. Typically developing males expressed smaller soma and less arborization than females in juvenility, but larger soma than females in adolescence. MS led to fewer microglia in the infralimbic PFC of adolescent males. Both MS and lipopolysaccharide administration affected morphological characteristics in juvenile males and females, with MS exposure leading to a greater increase in soma size following lipopolysaccharide. Interestingly, effects of MS and lipopolysaccharide were not observed in adolescence, while notable sex differences in PFC microglial morphology were apparent. Taken together, these findings provide insight into how PFC microglia may differentially respond to challenges over development in males and females.

The demersal bathyal fish assemblage of the Central-Western Mediterranean: Depth distribution, sexual maturation and reproduction

This study compiles information on the size distribution and reproductive patterns of five chondrichthyans and 10 bony species dwelling on the continental slope of the Central-Western Mediterranean (south-eastern Sardinian waters, depth 720–1890 m). The abundance of the relatively less numerous chondrichthyans was found to decrease with depth. Almost all chondrichthyan species had a long reproductive period throughout the year at all depths. In bony fishes, the upper bathymetric stratum (<1100 m) was dominated by species with continuous and seasonal (autumn-winter) spawning cycles. At intermediate and lower depths (>1100 m), continuous reproduction was the most common pattern. Both chondrichthyans and bony fishes exhibited large sizes at maturity and at first maturity (>75% and >60% of their maximum body length, respectively), supporting the hypothesis that most deep-sea fish populations are characterized by a delayed maturity, which makes them highly vulnerable to fishing pressure and over-exploitation. In some sharks, population partitioning was observed, according to life stage as a function of depth: adult/mature females occupied deeper habitats than males and juveniles. Conversely, Dipturus nidarosiensis female and male juveniles (>1100 m) were segregated from the adult/mature population, dwelling between 1000 and 1100 m. In four of the 10 bony fishes examined, we found a clear and significant predominance of females, particularly pronounced in Alepocephalus rostratus, which is clearly related to their K-reproductive strategy. The four key-selected species (Galeus melastomus, A. rostratus, Bathypterois mediterraneus and Trachyrincus scabrus), characterized by different reproductive strategies/modalities and feeding behaviours, were differently affected by depth and fluxes of organic matter (Particulate Organic Carbon concentration) from the photic zone towards the sea-bottom as a function of sex and life -stage.

Variation in Survival and Harvest Rates in Florida Mottled Duck

ABSTRACTThe Florida mottled duck (Anas fulvigula fulvigula) inhabits a relatively small range of approximately 90,000 km2 within peninsular Florida, USA, and is threatened by habitat loss and genetic introgression with feral mallards (Anas platyrhynchos). Moreover, the Florida mottled duck population status has not been assessed for more than a decade. We used band‐recovery and recapture data from 2000–2013 to examine geographic and demographic factors that influence the survival of Florida mottled ducks and to determine whether survival and harvest probabilities have changed over time. Mean survival probabilities were higher for birds banded in the southern portion of their Florida range than for those banded in the northern portion and higher for adult males than for adult females in both areas. Harvest probabilities increased in the northern extent of its range in Florida for adults and juveniles and remained relatively constant in the southern portion of its range during the study period. Mean harvest probabilities for adult males in both areas were higher than for adult females. Mean harvest probability for juvenile females was higher than that for juvenile males in the north but was similar between the sexes in the south. Our results suggest that mortality rates are generally greater in the northern portion of the Florida mottled duck range because of regional differences in habitat distribution and permanence and in how mottled ducks and humans use wetlands in these areas. We suggest increasing conservation efforts in the north portion of the Florida mottled duck range and improving inferences from leg banding by incorporating live recapture data. © 2020 The Wildlife Society.

Sexual traits and reproductive strategy of the leucosiid crab Pyrhila pisum

AbstractMating strategy and sexual dimorphism of morphological traits of the leucosiid crab Pyrhila pisum were elucidated by analysing relative growth patterns of chelipeds and abdomen, and gonad development patterns. Male adults had long chelipeds compared with juvenile males and females. Among male adults, two phases with different slopes could be found in the regression lines; their chelipeds growth pattern changed from negative allometry to positive and longer chelipeds developed in large adults. The growth is more markedly expressed in the merus than in the propodus. Female adults had wider abdominal segments and a thicker body compared with juvenile females and males. Abdomen of females was greatly enlarged by a puberty moult. Male adults had well-developed gonads similar to female adults, and the weights of male gonads were often larger than those of females of the same body size. For adult males, a negative correlation was detected between carapace width and the weight ratio of their gonads, but no significant relationship was detected for adult females. Females had large and well-bloated seminal receptacles, whose weight was nearly equal to gonad weight. There was little difference in the amount of seminal receptacles regardless of the body size of females. There is a trade-off relationship in the development between chelipeds and gonads in adult males. Probably young adult males compensate for the disadvantageous condition of guarding by increasing the number of spermatozoids, and old adult males invest more of their energy to their chelae for guarding while decreasing investment in sperm production.

Alterations in the gut-associated microbiota of juvenile Caribbean spiny lobsters Panulirus argus (Latreille, 1804) infected with PaV1

The spiny lobster Panulirus argus (Latreille, 1804) is currently affected by an unenveloped, icosahedral, DNA virus termed Panulirus argus virus 1 (PaV1), a virulent and pathogenic virus that produces a long-lasting infection that alters the physiology and behaviour of heavily infected lobsters. Gut-associated microbiota is crucial for lobster homeostasis and well-being, but pathogens could change microbiota composition affecting its function. In PaV1 infection, the changes of gut-associated microbiota are yet to be elucidated. In the present study, we used high-throughput 16S rRNA sequencing technology to compare the bacterial microbiota in intestines of healthy and heavily PaV1-infected male and female juveniles of spiny lobsters P. argus captured in Puerto Morelos Reef lagoon, Quintana Roo, Mexico. We found that basal gut-associated microbiota composition showed a sex-dependent bias, with females being enriched in amplicon sequence variants (ASVs) assigned to Sphingomonas, while males were enriched in the genus Candidatus Hepatoplasma and Aliiroseovarius genera. Moreover, the alpha diversity of microbiota decreased in PaV1-infected lobsters. A significant increase of the genus Candidatus Bacilloplasma was observed in infected lobsters, as well as a significant decrease in Nesterenkonia, Caldalkalibacillus, Pseudomonas, Cetobacterium and Phyllobacterium. We also observed an alteration in the abundances of Vibrio species. Results from this study suggest that PaV1 infection impacts intestinal microbiota composition in Panulirus argus in a sex-dependent manner.

Commentary on translational impact: Distinguishing between passive and active suicidal ideation to address the mental health needs of female juveniles.

Commentary on translational impact: Distinguishing between passive and active suicidal ideation to address the mental health needs of female juveniles.

Identification of a Growth-Associated Single Nucleotide Polymorphism (SNP) in Cyclin C of the Giant Tiger Shrimp Penaeus monodon.

The full-length cDNA of cyclin C of the giant tiger shrimp Penaeus monodon (PmCyC) was isolated by RACE-PCR. It was 1443bp in length containing an open reading frame (ORF) of 804bp and 267 deduced amino acids. Tissue distribution analysis indicated that PmCyC was more abundantly expressed in ovaries and testes than other tissues of female and male juveniles (P<0.05). A pair of primers was designed, and an amplification product of 403bp containing an intron of 123bp was obtained. Polymorphism of amplified PmCyC gene segments of the 5th (3-month-old G5, N=30) and 7th (5-month-old G7, N=18) generations of domesticated juveniles was analyzed. Four conserved SNPs (T>C134, T>C188, G>A379, and T>C382) were found within the examined sequences. A TaqMan genotyping assay was developed for detection of a T>C134 SNP. Association analysis indicated that this SNP displayed significant association with body weight (P<4.2e-10) and total length (P<2e-09) of the examined G7 P. monodon (N=419) with an allele substitution effect of 5.02±0.78g and 1.41±0.19cm, respectively. Juveniles with C/C134 (22.80±2.51g and 12.97±0.53cm, N=19) and T/C134 (20.41±0.93g and 12.77±0.21cm, N=129) genotypes exhibited a significantly greater average body weight and total length than those with a T/T134 genotype (14.72±0.53g and 11.37±0.13cm, N=271) (P<0.05).

The utility of self-reported psychopathic traits in predicting recidivism among a sample of incarcerated female youths

Only a few studies have prospectively examined the utility of self-reported measures of psychopathic traits in predicting criminal behavior among forensic samples of female youth offenders. The main aim of this study is to compare the utility of two self-report measures of psychopathic-like traits in predicting criminal recidivism among a sample of incarcerated female youths. Participants (N = 76) from the three nation-wide Portuguese juvenile detention centers that admit female youths were followed over two years and prospectively classified as recidivists versus non-recidivists. Logistic regression models controlling for crime frequency and ethnicity revealed that neither the Antisocial Process Screening Device – Self-Report (APSD-SR) nor the Youth Psychopathic Traits Inventory (YPI) and their respective dimensions significantly predicted one- and two-year general recidivism and violent recidivism. Findings mostly suggest there are clear limitations in terms of the incremental utility of self-report measures of psychopathic traits in predicting criminal recidivism among incarcerated female juveniles.

Sex differences in the acoustic features of social play-induced 50-kHz ultrasonic vocalizations: A detailed spectrographic analysis in wild-type Sprague-Dawley and Cacna1c haploinsufficient rats.

Sexual dimorphisms are widespread in the animal kingdom. At the behavioral level, there is evidence for sex differences in social play behavior. In rats, males typically engage more in rough-and-tumble play than females. One prominent component of the rough-and-tumble play repertoire in rats is the emission of 50-kHz ultrasonic vocalizations (USV). Such 50-kHz USV reflect the rewarding nature of play and serve as socioaffective signals. Here, we provide evidence for sexual dimorphisms within rough-and-tumble play-induced 50-kHz USV in juvenile rats. Specifically, females displayed reduced 50-kHz USV emission during playful interactions. This reduction was associated with changes in 50-kHz USV emission rates and subtype profiles during specific rough-and-tumble components, i.e., pinning, wrestling, and chasing, as well as differences in acoustic parameters. Interestingly, sex differences were modulated by Cacna1c, a gene strongly implicated in major neuropsychiatric disorders, often characterized by prominent sex biases, most notably autism. Specifically, Cacna1c haploinsufficiency affected the emission of 50-kHz USV during rough-and-tumble play in female rats and we provide evidence supporting the notion that such effects of Cacna1c haploinsufficiency are driven by male-typical features of 50-kHz USV emission. This is in line with the hypermasculinized social play repertoire previously observed in juvenile Cacna1c haploinsufficient females.

Increasing Chlamydia and Gonorrhea Infections among Female Juveniles: The Need for Collaboration to Improve Treatment.

Background: Youth in juvenile detention centers are at a high risk for sexually transmitted disease (STD). The current study assesses the trends of chlamydia and gonorrhea (GC) infections and treatment among females within a single county’s juvenile correctional facilities.Methods: This is a retrospective review of aggregate data of female adolescents between 12 and 18 years old who underwent STD screening from 2009 to 2016 in San Bernardino County.Results: Chlamydia infections among adolescent females increased from 11.8% in 2009 to 17.0% in 2016 (p = 0.0002), and GC infections increased from 1.3% in 2009 to 6.0% in 2016 (p < 0.0001). Treatment rates of chlamydia were stable, ranging from 66.7% to 70.8% of positive female adolescents were treated between 2009 and 2016 (p=0.1752). The treatment rate for GC increased from 33% in 2009 to 78.3% in 2016, but annual trends were not statistically significant (p=0.8419).Conclusions: Chlamydia and GC infections among female adolescents discovered during routine screening upon booking into a county juvenile detention system increased over the study time period. Effective collaboration between public health and various community organizations is needed to improve awareness and prevention of STDs amongst at-risk adolescents.

Juvenile-juvenile social signalling: a case for precocial sexual selection in the collared lizard,Crotaphytus collaris(Squamata: Crotaphytidae)?

AbstractSexual selection is widespread in animals, but quite naturally studied in adults. Juvenile males in most animals are not differentiated from females and coloration is usually drab. However, there is no reason to suspect that sexual differences cannot develop before puberty, influence social interactions, and then have fitness pay-offs later in life. Juvenile collared lizards (Crotaphytus collaris (Say, 1822)) show marked dichromatism: males develop bright dorsolateral orange bars whereas females do not. These juvenile orange bars (JOB) disappear at sexual maturity, when males develop different colour traits maintained by sexual selection. We conducted field experiments with juvenile males on their developing territories in which we utilized staged intruders of juvenile males (with JOB) and juvenile females (lacking JOB) and also juvenile male intruders whose JOB were manipulated. Residents reacted significantly more aggressively toward males vs. females, and also toward males whose JOB were emphasized with paint than those whose JOB were masked by paint. These JOB are used in signalling among juveniles and we suggest the social relations established then are retained until sexual maturation the next spring (after the JOB are lost) to benefit males that previously displayed strong JOB by increased matings in the spring as sexually mature yearlings as per a phenomenon we call precocial sexual selection.

Hers and his: Silk glands used in egg sac construction by female spiders potentially repurposed by a \u2018modern\u2019 male spider

Cylindrical silk gland (CY) spigots distinguish a large clade of modern spiders, the CY spigot clade, which includes all entelegyne spiders and their closest relatives. Following a widespread paradigm, CYs and their spigots are only known to occur in female spiders and they produce silk used in the construction of egg sacs. Here we report the occurrence of a CY spigot or CY nubbin on each posterior median spinneret (PMS) in males (5th stadium and later) of the spider Australomimetus maculosus. Late juvenile males had a CY spigot on each PMS, whereas adult males either had a CY spigot or, more often, a non-functional CY nubbin. This indicates that potential CY use by males is at least largely limited to late juvenile instars and is not involved with egg sac construction. Despite the presence of CY spigots in both sexes, sexual dimorphism with respect to CYs was still evident since males lacked the CY spigot on each posterior lateral spinneret present in late juvenile and adult females, and CY spigots of males never had the wide shaft and opening of adult females. This study adds to our knowledge of spinning apparatus variability in modern spiders and demonstrates an exception to the paradigm that, in the CY spigot clade, such spigots are restricted to female spiders.

Dissociated roles of dorsal and ventral hippocampus in recall and extinction of conditioned fear in male and female juvenile rats

Reduction of conditioned fear expression by extinction underlies cue exposure therapies that treat anxiety disorders. Extinction is context-specific. Renewal, for example, is the relapse of extinguished fear when subjects are tested in a different context to extinction. This context-specificity is developmentally regulated and sex-dependent, with renewal being observed in postnatal day (P) 18 female, but not in male, rats. Given the hippocampus (HPC) is critical for context-specific extinction in adult rodents, we investigated dorsal or ventral hippocampus (dHPC or vHPC) involvement in context-specific extinction in P18 male and female rats. We microinfused muscimol (GABAA agonist) to inactivate either structure before extinction, then tested rats for renewal the next day. Regardless of sex, dHPC inactivation accelerated extinction acquisition, while vHPC inactivation reduced fear expression during extinction and impaired extinction recall. Consistent with previous findings, renewal was observed in females but not in males. Surprisingly, inactivation of dHPC or vHPC had no effects on renewal in either sex, indicating that the hippocampus does not play a critical role in context-dependent extinction learning in juvenile rats. These findings are the first to demonstrate dissociated roles of dHPC and vHPC in conditioned fear expression and extinction in juvenile rats. In addition, context-specific extinction shown by juvenile females, but not males, likely is not due to potential sex differences in hippocampus involvement in extinction of conditioned fear in developing rats.

Normative ocular data for juvenile and adult Japanese quail (Coturnix japonica).

To obtain normative ocular data for Japanese quail as they mature from juveniles to adults. Twenty-six captive Japanese quail comprising thirteen males and thirteen females, free of ocular disease, were included in the study. Ophthalmic reference values were measured in both eyes at 1 and 5months of age. A complete ophthalmic examination was performed, including neuro-ophthalmic reflexes, slit lamp biomicroscopy, phenol red thread test (PRTT), rebound tonometry, fluorescein staining, horizontal corneal diameter measurement, indirect ophthalmoscopy, and ocular ultrasound biometry. Ultrasound biomicroscopy measurements of axial globe length, lens thickness, vitreal chamber length, and pecten length were recorded. The depth of the anterior chamber was calculated by subtracting the lens thickness and vitreous length from the axial globe length. Measures of association and descriptive statistics were analyzed using STATA-14 and STATA-15. Juvenile and adult females were heavier than age-matched males. Weight, intraocular pressure, horizontal corneal diameter, axial globe length, and lens thickness measurements increased with age. No statistically significant differences were found in the remainder of measurements among individuals in different sex or age-groups. This work provides reference values and clinical findings that can be used in future research on quail and ocular disease.