Critical Developmental Period Research Articles

Temperature-Dependent Sex Determination in Crocodilians and Climate Challenges.

The sex of crocodilians is determined by the temperature to which the eggs, and hence the developing embryo are exposed during critical periods of development. Temperature-dependent sex determination is a process that occurs in all crocodilians and numerous other reptile taxa. The study of artificial incubation temperatures in different species of crocodiles and alligators has determined the specific temperature ranges that result in altered sex ratios. It has also revealed the precise temperature thresholds at which an equal number of males and females are generated, as well as the specific developmental period during which the sex of the hatchlings may be shifted. This review will examine the molecular basis of the sex-determination mechanism in crocodilians elucidated during recent decades. It will focus on the many patterns and theories associated with this process. Additionally, we will examine the consequences that arise after hatching due to changes in incubation temperatures, as well as the potential benefits and dangers of a changing climate for crocodilians who display sex determination based on temperature.

Discrimination experiences and problematic alcohol and cannabis use in young adulthood.

Limited research has examined how discrimination in young adulthood relates to substance use. We examined how multiple and specific types (e.g., race-based) of experiences of unfair treatment are related to problematic alcohol and cannabis use. We analyzed cross-sectional data from a diverse cohort of young adults (mean age 24.7) predominantly residing in southern California (n = 2303) to examine associations of multiple (count) and specific experiences (race-, sexual orientation-, gender-based) of perceived everyday discrimination with self-reported alcohol and cannabis use outcomes (consequences, use disorders, and solitary use). We also tested interactions between the three specific discrimination experiences and sociodemographic characteristics (e.g., race-based discrimination × race/ethnicity). In this diverse sample (e.g., 47% Latinx/o and 22% Asian; 22% sexual/gender diverse; 56% female) of young adults, about 46% reported up to four different discrimination experiences and 27% reported race-, 26% gender-, and 5% sexual orientation-based discrimination. Race- and gender-based discrimination and experiencing more types of discrimination were associated with worse cannabis use outcomes. Race-based discrimination was associated with fewer alcohol consequences and lower Alcohol Use Disorders Identification Test (AUDIT) scores. Associations with sexual orientation-based discrimination and the interactions were not significant. Findings build on limited research on associations of discrimination with cannabis use in young adults. More work is needed to understand the mechanisms by which discrimination influences drinking behaviors. This study advances the field by examining the unique contributions of specific and multiple types of discrimination experiences in young adulthood, a critical developmental period in which substance use peaks.

Research progress on the association between screen content and mental health issue in children and adolescents

With the wide use of screen media, screen exposure shows a trend of younger age, and the screen exposure of children and adolescents has become a global public health issue of concern. Childhood and adolescence are important stages of growth and development, as well as critical periods of cognitive ability, emotional development and socialization. Previous studies have shown that screen time is closely related to the mental health of children and adolescents, but few studies have focused on the correlation between screen content and their mental health. The screen content for children and adolescents mainly comes from traditional TV and emerging interactive electronic media. Children and adolescents are highly sensitive to screen content. This paper summarizes the current situation of screen content for children and adolescents and reviews the correlation between screen content and their mental health issues. It also reveals the potential mechanism of the correlation between the two to provide a theoretical basis for the selection and supervision of screen content for children and adolescents.

Adaptation and Validation of the Post-Pandemic Health Promotion Behavior of Young Adults in the Digital Age (PS-SGD) Scale in the Turkish Population.

Young adulthood is a critical developmental period in which individuals establish life-long health behaviors and take responsibility for their own health care. Health promotion strategies tailored to young adults, leveraging digital tools, and addressing challenges exacerbated by events like the COVID-19 pandemic are needed. The aim of this study was to adapt the post-pandemic health promotion behavior of young adults in the digital age (PS-SGD) scale to the Turkish population in order to assess and compare the health behavior of young adults after the pandemic. A total of 312 participants, aged between 19 and 29 years, were included in the study via non-probabilistic criterion sampling, while the Turkish adaptation process started with translation and back translation methods performed with three language and two health science experts. For statistical analysis, EFA and CFA were conducted to evaluate internal consistency and structural validity. Confirmatory factor analysis was utilized to confirm the structure of the six sub-dimensions. Additionally, measurement invariance was examined regarding participants' gender to determine if the scale accurately captured similar traits across diverse groups. The relationship between the test-retest data was tested by Pearson correlation to measure consistency and its invariance over time. The gender distribution of the sample was found to be 61.3% female and 38.7% male. According to the results of EFA, items 8 and 18 were removed from the Turkish-adapted version. As a result of the reliability analysis conducted with the Turkish version of the scale, the Cronbach alpha coefficient was obtained as 0.851 for the post-pandemic health promotion behavior. Additionally, the scale was rated as reliable with the following Cronbach alpha values: 0.79 for the "personal hygiene", 0.78 for "dietary habits", 0.72 for "using mobile devices", 0.70 for "emotional health", 0.68 for "health care and physical activity", and 0.51 for "social health" sub-dimensions. To examine the six sub-dimension factor structures of the scale, fit indices were calculated as χ2/df (1.722), GFI (0.894), IFI (0.908), TLI (0.892), CFI (0.907), RMSEA (0.048), and SRMR (0.057) and were within acceptable limits. Findings of the multi-group confirmatory factor analysis for measurement invariance were less than or equal to 0.01 for the ∆CFI and ∆RMSEA values across all indices. Consequently, it was observed that the item-factor structure, factor loadings, variances, covariances, and error variances of the scale were equivalent for both male and female young adults, while test-retest results showed a high positive correlation. The Turkish version of the post-pandemic health promotion behavior scale of young adults in the digital age scale, consisting of 25 items and six subscales, was proven to be a valid and reliable tool to measure health promotion behavior in young adults aged 19-29 years.

Glia control experience-dependent plasticity in an olfactory critical period.

Sensory experience during developmental critical periods has lifelong consequences for circuit function and behavior, but the molecular and cellular mechanisms through which experience causes these changes are not well understood. The Drosophila antennal lobe houses synapses between olfactory sensory neurons (OSNs) and downstream projection neurons (PNs) in stereotyped glomeruli. Many glomeruli exhibit structural plasticity in response to early-life odor exposure, indicating a general sensitivity of the fly olfactory circuitry to early sensory experience. We recently found that glia regulate the development of the antennal lobe in young adult flies, leading us to ask if glia also drive experience-dependent plasticity. Here we define a critical period for structural and functional plasticity of OSN-PN synapses in the ethyl butyrate (EB)-sensitive glomerulus VM7. EB exposure for the first two days post-eclosion drives large-scale reductions in glomerular volume, presynapse number, and post-synaptic activity. The highly conserved engulfment receptor Draper is required for this critical period plasticity. Specifically, ensheathing glia upregulate Draper expression, invade the VM7 glomerulus, and phagocytose OSN presynaptic terminals in response to critical-period EB exposure. Crucially, synapse pruning during the critical period has long-term consequences for circuit function since both OSN-PN synapse number and spontaneous activity of PNs remain persistently decreased. These data demonstrate experience-dependent pruning of synapses in olfactory circuitry and argue that the Drosophila antennal lobe will be a powerful model for defining the function of glia in critical period plasticity.

Floral Response to Heat: A Study of Color and Biochemical Adaptations in Purple Chrysanthemums.

Chrysanthemums are among the world's most popular cut flowers, with their color being a key ornamental feature. The formation of these colors can be influenced by high temperatures. However, the regulatory mechanisms that control the fading of chrysanthemum flower color under high-temperature stress remain unclear. This study investigates the impact of high temperatures on the color and biochemical responses of purple chrysanthemums. Four purple chrysanthemum varieties were exposed to both normal and elevated temperature conditions. High-temperature stress elicited distinct responses among the purple chrysanthemum varieties. 'Zi Feng Che' and 'Chrystal Regal' maintained color stability, whereas 'Zi Hong Tuo Gui' and 'Zi lian' exhibited significant color fading, particularly during early bloom stages. This fading was associated with decreased enzymatic activities, specifically of chalcone isomerase (CHI), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS), indicating a critical period of color development under heat stress. Additionally, the color fading of 'Zi Lian' was closely related to the increased activity of the peroxidase (POD) and polyphenol oxidase (PPO). Conversely, a reduction in β-glucosidase (βG) activity may contribute significantly to the color steadfastness of 'Zi Feng Che'. The genes Cse_sc027584.1_g010.1 (PPO) and Cse_sc031727.1_g010.1 (POD) might contribute to the degradation of anthocyanins in the petals of 'Zi Hong Tuo Gui' and 'Zi Lian' under high-temperature conditions, while simultaneously maintaining the stability of anthocyanins in 'Zi Feng Che' and 'Chrystal Regal' at the early bloom floral stage. The findings of this research provide new insights into the physiological and biochemical mechanisms by which chrysanthemum flower color responds to high-temperature stress.

Chronic Adolescent Restraint Stress Downregulates miRNA-200a Expression in Male and Female C57BL/6J and BALB/cJ Mice.

Adolescence is a critical developmental period when the brain is plastic, and stress exposure can have lasting physiological consequences. One mechanism through which adolescent stress may have lasting effects is by altering microRNAs (miRNAs), leading to wide-scale gene expression changes. Three prior independent studies used unbiased approaches (RNA sequencing or microarray) to identify miRNAs differentially expressed by chronic variable stress in male rodents. In all three studies, miRNA-200a was differentially expressed in areas of the brain associated with emotion regulation. The current study extends this research to determine if chronic non-variable adolescent stress downregulates miRNA-200a expression by looking at two strains (BALB/cJ and C57BL/6J) of male and female mice. We utilized a 14-day (2 h/day) restraint stress protocol and verified stress effects on adolescent body weight gain and circulating corticosterone concentrations relative to non-restraint controls. Mice were then left undisturbed until they were euthanized in adulthood, at which time brains were collected to measure miRNA-200a in the ventral hippocampus. Three weeks after adolescent stress ended, differences in body weight between groups were no longer significant; however, animals exposed to stress had less miRNA-200a expression in the ventral hippocampus than control animals. These data implicate miRNA-200a expression as a potential mechanism by which adolescent stress can have persistent impacts on multiple outcomes in both male and female mice.

Tutor auditory memory for guiding sensorimotor learning in birdsong.

Memory-guided motor shaping is necessary for sensorimotor learning. Vocal learning, such as speech development in human babies and song learning in bird juveniles, begins with the formation of an auditory template by hearing adult voices followed by vocally matching to the memorized template using auditory feedback. In zebra finches, the widely used songbird model system, only males develop individually unique stereotyped songs. The production of normal songs relies on auditory experience of tutor's songs (commonly their father's songs) during a critical period in development that consists of orchestrated auditory and sensorimotor phases. "Auditory templates" of tutor songs are thought to form in the brain to guide later vocal learning, while formation of "motor templates" of own song has been suggested to be necessary for the maintenance of stereotyped adult songs. Where these templates are formed in the brain and how they interact with other brain areas to guide song learning, presumably with template-matching error correction, remains to be clarified. Here, we review and discuss studies on auditory and motor templates in the avian brain. We suggest that distinct auditory and motor template systems exist that switch their functions during development.

Dopamine receptors and key elements of the neurotrophins (BDNF, CDNF) expression patterns during critical periods of ontogenesis in the brain structures of mice with autism-like behavior (BTBR) or its absence (С57BL/6 J).

Analysis of the mechanisms underlying autism spectrum disorder (ASD) is an urgent task due to the ever-increasing prevalence of this condition. The study of critical periods of neuroontogenesis is of interest, since the manifestation of ASD is often associated with prenatal disorders of the brain development. One of the currently promising hypotheses postulates a connection between the pathogenesis of ASD and the dysfunction of neurotransmitters and neurotrophins. In this study, we investigated the expression of key dopamine receptors (Drd1, Drd2), brain-derived neurotrophic factor (Bdnf), its receptors (Ntrkb2, Ngfr) and the transcription factor Creb1 that mediates BDNF action, as well as cerebral dopamine neurotrophic factor (Cdnf) during the critical periods of embryogenesis (e14 and e18) and postnatal development (p14, p28, p60) in the hippocampus and frontal cortex of BTBR mice with autism-like behavior compared to the neurotypical C57BL/6 J strain. In BTBR embryos, on the 14th day of prenatal development, an increase in the expression of the Ngfr gene encoding the p75NTR receptor, which may lead to the activation of apoptosis, was found in the hippocampus and frontal cortex. A decrease in the expression of Cdnf, Bdnf and its receptor Ntrkb2, as well as dopamine receptors (Drd1, Drd2) was detected in BTBR mice in the postnatal period of ontogenesis mainly in the frontal cortex, while in the hippocampus of mature mice (p60), only a decrease in the Drd2 mRNA level was revealed. The obtained results suggest that the decrease in the expression levels of CDNF, BDNF-TrkB and dopamine receptors in the frontal cortex in the postnatal period can lead to significant changes in both the morphology of neurons and dopamine neurotransmission in cortical brain structures. At the same time, the increase in p75NTR receptor gene expression observed on the 14th day of embryogenesis, crucial for hippocampus and frontal cortex development, may have direct relevance to the manifestation of early autism.

Purinosomes and Purine Metabolism in Mammalian Neural Development: A Review.

Neural stem/progenitor cells (NSPCs) in specific brain regions require precisely regulated metabolite production during critical development periods. Purines-vital components of DNA, RNA, and energy carriers like ATP and GTP-are crucial metabolites in brain development. Purine levels are tightly controlled through two pathways: de novo synthesis and salvage synthesis. Enzymes driving de novo pathway are assembled into a large multienzyme complex termed the "purinosome." Here, we review purine metabolism and purinosomes as spatiotemporal regulators of neural development. Notably, around postnatal day 0 (P0) during mouse cortical development, purine synthesis transitions from the de novo pathway to the salvage pathway. Inhibiting the de novo pathway affects mTORC1 pathway and leads to specific forebrain malformations. In this review, we also explore the importance of protein-protein interactions of a newly identified NSPC protein-NACHT and WD repeat domain-containing 1 (Nwd1)-in purinosome formation. Reduced Nwd1 expression disrupts purinosome formation, impacting NSPC proliferation and neuronal migration, resulting in periventricular heterotopia. Nwd1 interacts directly with phosphoribosylaminoimidazole-succinocarboxamide synthetase (PAICS), an enzyme involved in de novo purine synthesis. We anticipate this review will be valuable for researchers investigating neural development, purine metabolism, and protein-protein interactions.

Adolescents’ short-form video addiction and sleep quality: the mediating role of social anxiety

BackgroundAdolescence is a critical period for individual growth and development. Insufficient sleep adversely affects adolescents’ physical development, blood pressure, vision, and cognitive function. This study examined the effect of short-form video addiction on adolescents’ sleep quality, as well as the mediating role of social anxiety, to identify methods for improving adolescents’ sleep quality in the Internet era.MethodsA questionnaire survey was conducted in this cross-sectional study on 1629 adolescents recruited from three high schools. Their short-form video addiction, social anxiety, and sleep quality were evaluated using corresponding scales. Pearson correlation analysis was carried out to analyze the relationships among short‐form video addiction, sleep quality, and social anxiety. Mediating effect analysis was constructed using AMOS 20.0 statistical software.ResultsParticipants’ sleep quality score is 6.12 ± 3.29 points. The detection rate of sleep quality among them is 31.06%. Short‐form video addiction, sleep quality, and social anxiety are significantly correlated (r = 0.439, 0.404, 0.457, P < 0.001). The direct effect of short-form video addiction on sleep quality is 0.248, accounting for 62.4% of the total effect. The indirect effect exerted through social anxiety is 0.149, accounting for 37.6%.ConclusionsSleep disorders are very common among Chinese adolescents. Short‐form video addiction is positively correlated with adolescents’ sleep quality and social anxiety. Social anxiety partially mediates the relationship between short-form video addiction and sleep quality. The adverse effects of short-form video addiction and social anxiety on the sleep quality of this group must be minimized. Schools are recommended to implement measures to promote sleep quality among adolescents.

Aberration of social behavior and gut microbiota induced by cross-fostering implicating the gut-brain axis

The gut microbiota and neurological development of neonatal mice are susceptible to environmental factors that may lead to altered behavior into adulthood. However, the role that changed gut microbiota and neurodevelopment early in life play in this needs to be clarified. In this study, by modeling early-life environmental changes by cross-fostering BALB/c mice, we revealed the effects of the environment during the critical period of postnatal development on adult social behavior and their relationship with the gut microbiota and the nervous system. The neural projections exist between the ascending colon and oxytocin neurons in the paraventricular nuclei (PVN), peripheral oxytocin levels and PVN neuron numbers decreased after cross-fostering, and sex-specific alteration in gut microbiota and its metabolites may be involved in social impairments and immune imbalances brought by cross-fostering via the gut-brain axis. Our findings also suggest that social cognitive impairment may result from a combination of PVN oxytocinergic neurons, gut microbiota, and metabolites.

Sounding the alarm regarding mental health of children and adolescents in relation to parenting style

BackgroundChildhood and adolescence are critical periods for physical and mental development. For that, sounding the alarm for the warning signs and red flags of children’s mental health disorders is important to promote good health and mental wellness throughout the lifespan. The aim of the study was to assess children’s and adolescents’ mental health in relation to parenting styles.MethodsThis study used a descriptive cross-sectional design. From early May 2022 until late October 2022, Zagazig University in Egypt hosted this investigation. Subjects: For this study, 400 parents of Zagazig University staff, employees, and workers who agreed to engage in the current study were gathered as a convenience sample. Tools: In order to get the required data, three tools were utilized. Tool I: A questionnaire for interviews to gather demographic information about the participating parents and their children. Tool II: Adapted Ontario Child Health Study Emotional Behavioural Scale: Parent Version (for children 4–17 years). Tool III: Parenting style scale.ResultsIt was found that criteria for conduct disorder constituted the highest followed by criteria for attention deficit hyperactivity disorder and major depression disorder with a mean and standard deviation of 15.10 ± 3.7, 12.83 ± 3.4, and 11.9 ± 2.8. Also, 66% of the participating parents practiced a permissive parenting style while 18% of them practiced the authoritative style and 16% for the authoritarian style.ConclusionIt was determined that criteria of conduct disorder were the most prevalent, followed by criteria of attention deficit hyperactivity disorder and major depressive disorder. Additionally, there was high statistical significance between mental health disorders, parenting styles, and parental educational level. In order to protect children’s and adolescents’ mental health, this study recommended alerting parents and teachers about red flags and warning signs of mental health disorders for early detection and management. Additionally, educate parents about effective parenting methods and how to behave correctly with their children. Psychological counseling centers for seeking help should be available everywhere and announced.

'Do it afraid': An arts-based reflexive collective case study exploring youth responses to post-concussion communication changes in daily life.

Concussion and communication researchers have yet to study how post-concussion communication changes affect youths' daily lives. The lack of attention paid to how young people respond to communication changes during concussion recovery constitutes a significant gap in current concussion management research and practices. To explore how youth respond to the effects of post-concussion communication changes in their daily life, including (1) daily routines, (2) relationships with family members, (3) relationships with peers and (4) participation in school/work and community activities. Five youths (16-25 years) and three family members participated in this arts-based reflexive collective case study. Ecocultural theory provided the theoretical framework for study design, data collection and analysis. Cases consist of (1) pre-interview demographic information, (2) three 60-90-min virtual interviews, (3) optional family member interviews, (4) multi-media arts-based participant-generated materials representing participants' experiences of communication change and concussion, and (5) researcher observations, discussions and reflexive journal entries. Reflexive thematic analysis was used to analyse the data. Analysis yielded four themes that illustrate the ways youth navigated and adapted to post-concussion communication changes: (1) navigating changes in communication tasks, daily roles, and identity; (2) re-negotiating relationships and emotional reactions; (3) seeking control and learning to let go during recovery; and (4) helping youth adapt to post-concussion communication changes. The study findings deepen our understanding of the impact of post-concussion communication changes on youths' daily lives and underscore considerations critical to the development ofcommunication-focused concussion education programs and interventions tailored specifically for youth. What is already known on the subject Youth is a critical period of social and emotional development. Communication is integral to identity, relationships, participation in daily activities and well-being. Concussions can affect speech clarity, fluency, understanding and use of language, and social interactions. Re-engaging in routine activities and pre-injury roles can be challenging for youth experiencing communication changes as part of complex concussion recoveries. What this paper adds to the existing knowledge Findings from this research illuminate how youth navigate and adapt to communication changes post-concussion and support the development of youth-focused communication education programs, assessments and interventions. Youth participants actively managed their recoveries by developing innovative strategies to support their communication during daily activities, learning about communication, practicing communication tasks sequentially, and facing fears. Youth also reframed and challenged narrow views of 'normal communication'. What are the potential or actual clinical implications of this work? Findings highlight the need for more youth- and communication-focused education materials and programs within youth concussion management protocols. Information about the specific ecological and sociocultural factors youth encounter during concussion recovery is needed to develop targeted communication-focused education and intervention programs for youth and their families to mitigate risks of isolation, loneliness, and mental health concerns and increase youths' participation in family, community and cultural life. By learning from youth about how communication changes affected their participation in daily activities, identity and relationships, clinicians can provide information and interventions to reduce adverse listener reactions and help young people feel supported and understood.

Efficacy of a Remote Play-Based Intervention for Children With Prader-Willi Syndrome.

The current study examines the efficacy of an 8-week pretend play intervention targeting social-cognitive abilities in children with Prader-Willi syndrome (PWS), ages 6-9. PWS is a rare disorder associated with various social, emotional, and cognitive challenges linked to pretend play impairments, and for which interventions are sparse. Nineteen children were quasi-randomized to receive the intervention or be part of a waitlist control group. Participants who received the intervention (n = 10) demonstrated significant improvements in various components of pretend play, most notably in organization of play, which may generalize to broader social-cognitive gains. These findings provide evidence of the intervention's efficacy in enhancing pretend play skills and related social-cognitive abilities during this critical period of development for children with PWS.

A novel developmental critical period of orexinergic signaling in the primary visual thalamus

The orexinergic system of the lateral hypothalamus plays crucial roles in arousal, feeding behavior, and reward modulation. Most research has focused on adult rodents, overlooking orexins' potential role in the nervous system development. This study, using electrophysiological and molecular tools, highlights importance of orexinergic signaling in the postnatal development of the rodent dorsolateral geniculate nucleus (DLG), a primary visual thalamic center. Orexin activation of DLG thalamocortical neurons occurs in a brief seven-day window around eye-opening, concurrent to transient OX2 receptor expression. Blocking OX2 receptors during this period reduces sensitivity of DLG neurons to green and blue light and lowers spontaneous firing rates in adulthood. This research reveals critical and temporally confined role of orexin signaling in postnatal brain development, emphasizing its contribution to experience-dependent refinement in the DLG and its long-term impact on visual function.

Parents and caregivers as key players in the prevention and identification of body image concerns and eating disorders among early adolescents

ABSTRACT Early adolescence (ages 11–14 years) is a key period for the emergence of body image and eating concerns, and early identification and access to treatment are imperative for positive outcomes. Despite research identifying this critical developmental period, few prevention resources are available for early adolescents. Parents are key players for this age group and important socializing agents. As such, they are well positioned to help youth access resources or support where needed. However, programs to position and involve parents as interventionists are lacking. Our aims are two-fold. First, we review the evidence for the effectiveness of parents as body image interventionists and the existing data regarding parental needs. Second, we provide directions for future research and outline a framework for empowering parents as interventionists, identifying key domains in which parents may play a role in addressing body image and eating concerns among early adolescents. Based on the extent literature, these domains include facilitating engagement with or co-utilizing intervention content to decrease body image and eating concerns in at-risk children, which may also help to increase parents’ effectiveness in their efforts to support youth. In addition, parents may deliver content to decrease or reverse risk-factors and early symptoms, or disrupt the early disorder phase of illness. To date, parents constitute an underutilized resource in eating disorder and disordered eating prevention, and efforts should be made to increase the evidence-based strategies to leverage their relationship with at-risk children.

2045-LB: Target-Derived Factors Decrease Sympathetic Innervation of Brown Adipose Tissue in a Critical Period of Development

2045-LB: Target-Derived Factors Decrease Sympathetic Innervation of Brown Adipose Tissue in a Critical Period of Development

Пубертатний стрес спричиняє статевоспецифічні репродуктивні ефекти у дорослих щурів

Adolescence is one of the critical periods of individual development, which is highly sensitive to changes caused by stress factors. Stress-related hormonal imbalances can negatively affect puberty and reproductive function. The aim of the study was to investigate the long-lasting reproductive effects of chronic pubertal stress in rats. Animals were subjected to immobilization stress daily from 30 to 45 postnatal day by placing them for 1 h in cylinders 4.5 cm in diameter and 10 cm in long, equipped with breathing holes. The timing of puberty in animals was studied and their somatic development was assessed. Further studies were conducted in 6-month-old sexually mature rats. The results were compared with the corresponding parameters in intact animals. Pubertal stress delayed sexual maturation in females and decreased weight gain in males. In adult animals of both sexes, pubertal stress did not change testosterone levels or the weight and morphology of the gonads significantly, except for minor vacuolation of the spermatogenic epithelium. The spermatogenesis index in the experimental group was significantly lower than in the control, due to a decrease in the number of late spermatids. Pubertal stress led to a 25.9% decrease in the number of spermatozoa in epididymal washes, an increase in the number of their pathological forms and a 2.4-fold slowdown in oxidative-reductive processes in spermatozoa. The content of malonic dialdehyde increased in the testes and ovaries, which indicates the activation of lipid peroxidation. Thus, chronic pubertal stress led to a decrease in the reproductive potential of male rats. Females are less susceptible to the negative effects of pubertal stress.

Pricing the priceless childcare: Early childhood education for babies and toddlers.

This article connects Viviana Zelizer's theory of the social meaning of money to family studies, using the case of American parents' spending on children. We investigate how money spent on the youngest children-babies and toddlers-reflects the growing expert emphasis on the importance of parental investment in the critical early period for child development. First, we review literature on expert knowledge to trace the shift in increasing emphasis on the importance of building children's cognitive skills through formal education beginning in infancy, offered in center-based care, moving from spaces of "childcare" to "early childhood education" centers. Second, we use quantitative data from the Consumer Expenditure Survey (1995-2017) to show that parents have increasingly spent money, and an increasing share of their income, on center-based care for babies and toddlers but not on otherchild items. Additionally, lower income families have been spending a greater share of their income on center-based care for their infants than other families. We interpret our findings using Zelizer's theory about the cultural influences on the meaning of money, showing how these can be expert-led and persist even when families are faced with structural economic constraints.