Sensitive Period Of Life Research Articles

Assessment of the frequency of fruit and vegetable consumption and adolescents’ knowledge of their benefits in Ain Temouchent (Western Algeria)

BACKGROUND: Adolescence is a critical and sensitive period of life, a fundamental stage of development, and special attention must be paid to the quality of food. Healthy eating habits at adolescence can be an important factor for healthy eating habits later in life. OBJECTIVE: To assess the frequency and knowledge of fruit and vegetable consumption among adolescents in Ain Temouchent (Western Algeria). METHODS: A study was conducted from February 1 to April 30, 2022. 103 adolescents responded to the questionnaire. The participants were boys (n = 48) and girls (n = 55) aged 12 to 18 years from two educational levels (middle school and high school). RESULTS: Adolescents surveyed had a mean BMI equal to 23.2 (kg/m2), considered overweight. The frequency of fruit and vegetable consumption it does not differ between girls and boys (p > 0.05). The consumption of fruits and vegetables was below recommended levels. The evaluation showed that most adolescents do not have a good knowledge of food composition and are not interested in fruits and vegetables in their daily diet (p > 0.05). CONCLUSION: This study showed that adolescents consume few fruits and vegetables, and they have little knowledge of the value of fruits and vegetables in their daily diet.

Mentalno zdravlje studentske populacije tokom pandemije COVID-19

The COVID-19 pandemic has not only affected the physical but also the mental health and well-being, causing many mental problems in the population around the world. This paper is trying to offer answers to questions about the impact of the pandemic on the level of stress, anxiety, depression and life satisfaction of the student population. The survey was conducted as a cross-sectional study. The studied population comprised students of the Faculty of Mechanical and Civil Engineering in Kraljevo and the Kraljevo Medical College. The standardised depression, anxiety and stress self-assessment scale - DASS-21 was used as the survey instrument. The largest number of students felt the fear of one of their relatives getting infected (80.2%), that is of endangering their family (77.6%). Approximately one in three students felt the fear of death (34.4%), the fear of getting infected (29.7%) and of ending up in hospital (36.5%). One in six respondents felt vulnerable during the state of emergency (16.3%), and one in ten felt very vulnerable (9.8%). 14.6% of them stated that the epidemic had affected their student responsibilities a lot, and 22.3% of students expressed the negative impact of isolation on them. The results of our study indicate a high percentage of reported symptoms of stress (44.2%), anxiety (47.1%) and depression (34.9%) among the student population. Pandemic conditions have led to considerable changes in the daily life of all people, while the impact of the pandemic and the consequences that are yet to emerge still cannot be fully understood. That is why it is of utmost importance to take care of the mental health of those who are in a sensitive period of life.

Responsiveness level and its effect on services quality from the viewpoints of the older adults hospitalized during COVID-19 pandemic

BackgroundAging is a sensitive period of life. Attention to the needs of this stage is considered a social necessity. This study is conducted to investigate the responsiveness level and its effect on service quality from the hospitalized older adults’ viewpoints during the COVID-19 pandemic in the south of Iran.MethodsIt was a cross-sectional descriptive-analytic study that was conducted on 386 old patients. The study instrument was a standard questionnaire that includes three sections of demographic information, World Health Organization Responsiveness, and SERVQUAL. Data were analyzed applying descriptive and inferential statistics the same as Independent T-test, ANOVA, Pearson correlation, and multiple linear regression.ResultsThe mean levels of responsiveness and service quality were 90.72 ± 9.38 (from 160) and 68.01 ± 8.51 (from 110) respectively. This indicates the average level of these variables from the old patients’ viewpoints. There was a significant positive correlation between responsiveness and service quality (r = 0.585). According to the results of multiple linear regression, the dimensions of communication, dignity, prompt attention, primary facilities, social support, information confidentiality, right to choose, and autonomy were identified as the predictors of service quality.ConclusionThe average level of responsiveness and service quality perceived from the old patients’ viewpoints during the COVID-19 pandemic can be considered a necessity for supportive planning among the older adults. Meanwhile, according to the impacts of responsiveness on service quality, educational programs are recommended to promote the level of healthcare providers’ responsiveness.

Energy and macronutrients intake in an Italian infants cohort at 24 months of age

Abstract Background Dietary habits during infancy and early childhood could have short and long-term health effects and could influence future adults' dietary habits. Acting during this sensitive period of life could be crucial. In 2006 a prospective infants cohort study was established at the Maternal and Child Institute - Burlo Garofolo in Trieste, Italy (Trieste Infant Feeding Cohort - TIF cohort) to assess energy and nutrients intake during the first three years of infants' life. This nutritional analysis focused on dietary habits of infants at 24 months of age. Methods Dietary data were collected using a 3-day dietary record (3-d DR) and data were analysed using a nutritional software containing the Italian Food Composition database and integrated with data from nutritional labels and literature. Energy and macronutrients intake were compared with the Italian Dietary Reference Values (DRV) and the WHO recommendation. Differences by sex were also assessed. Results 3d-DR was filled for 157 infants. Available carbohydrates (CHO) and starch intakes were significantly significant higher in males (p < 0.05). The percentage contribution of CHO to total energy intake was in line with DRV (75.8% of infants within the reference interval (RI)) similarly 75.2% of infants are within the RI for fats. Proteins' contribution to energy intake, instead, was above the RI for 53.5% of infants over the RI and the daily protein intake was greater than the estimated DRV (median 43.9 g/d, IQR of 16.2 g/d vs median DRV 10.3 g/d, IQR 1.3 g/d). Conclusions The results show a substantial adherence with recommendations for macronutrient intakes except for the excess protein intake. Elevated protein intake play a role in developing long-term health consequences and seems linked to overweight and obesity. Further evaluation of protein intake should be desirable. Key messages Nutritional studies are essential tools to assess dietary habits in infants and allow to contribute of reference recommendations evolution. Macronutrients analysis, with a particular focus on proteins intake, can help to evaluate children’ dietary patterns, to intercept and possibly correct unhealthy habits.

Musculoskeletal Changes Across the Lifespan: Nutrition and the Life-Course Approach to Prevention

Aging is characterized by the progressive decline of muscle mass and function, the so-called sarcopenia. Also bone loss is widespread among older people. Sarcopenia and osteopenia/osteoporosis are associated with several adverse outcomes including falls, risk of fractures, functional decline, frailty, and mortality. Recently, the life-course approach to prevent or delay functional decline has become very popular. Regarding musculoskeletal health, there is suggestive evidence that acting during critical or sensitive periods of life in which each person build-up its biological reserves may influence the rate of functional decline in the later stages of life. A life-course approach to musculoskeletal health should take place during early life when plasticity allows more easily the attainment of the peak of the musculoskeletal system driven by environmental stimuli. The rate of the subsequent decline will depend on the peak previously reached. Nutrition and physical exercise are important environmental factors that can influence musculoskeletal development by favoring and maintaining peak bone and muscle mass and strength. Here we provide an overview of body composition changes occurring across the lifespan and strategies based on nutrition and physical exercise to support musculoskeletal health as well as minimizing losses during older life.

Body image perception and body composition in early adolescents: a longitudinal study of an Italian cohort

BackgroundAdolescence is a sensitive period of life in which everyone faces physical and psychological changes. No longitudinal studies considering changes in body image perception and body composition in Italian adolescents have been carried out. The aims of this study were to evaluate the longitudinal change in body composition and weight status in a sample of Italian students of both sexes over the 3 years of middle school and to analyse the influence of these parameters on the perception and satisfaction of one’s own body image.MethodsSixty-four males and seventy females were followed longitudinally from 11 to 14. Age at first measurement was 11.8 ± 0.3 yrs. in males and 11.9 ± 0.3 yrs. in females, then the students were measured again after 1 year and 2 years. Anthropometric measurements were collected and body composition was assessed by skinfolds. Maturity status was detected by age at menarche in females and by estimated age at peak height velocity in males; sports practice was assessed by a questionnaire. Body Silhouette Charts were used to assess body image perception. The degree of body image dissatisfaction and improper perception of weight status were evaluated. Univariate and multivariate analyses were applied.ResultsHeight, sitting height, leg length, and weight increments were higher in males than in females, and in both sexes the sitting height increment was higher than that of leg length. Skinfold thicknesses and percentage of body fat, showed a decrease in males and an increase in females over the 3 years. About 90% of the sample practiced sport during the 3 years. No significant variations in body image perception were observed among repeated measures but significantly differences were observed between sexes. Although the girls showed a lower incidence of overweight and obesity than boys, girls had a higher dissatisfaction than males. Males were less accurate in one’s perception of one’s own weight status.ConclusionsThe changes in body composition observed in the sample of the present study were in accordance with their maturity stage. An increase in parameters connected with adiposity is observed in females and a decrease in males. Body image perception did not seem to change with growth, but associations were found between body image perception and BMI and sex. Monitoring body image perception in young adolescents, especially in females and in overweight/obese subjects, is a priority to prevent nutritional disorders.

Physical Health Needs of High School Female Adolescents and Related Factors in Tabriz in 2020

BackgroundAdolescence is a very important and sensitive period of life and paying attention to the health of this period is of particular importance. Therefore, paying attention to the health of female adolescents, as future mothers, is doubly important.ObjectivesThis study was performed aiming to determine the physical health needs of female adolescents and related factors in the city of Tabriz, Iran.MethodsThis descriptive-analytical study was performed on 435 high school female adolescents in the city of Tabriz using two-stage sampling method, in 2020. A demographic information form and the Female Adolescents Health Needs Questionnaire (FAHNQ; Shah Hosseini et al.) as a native questionnaire (validity=0.92, reliability=0.90) were used to collect data. Data analysis was performed by one-sample t-test, independent t-test, analysis of variance (ANOVA), and Duncan’s post hoc test using SPSS software version 16.ResultsAccording to the findings, 90.34% and 9.66% of the samples attended public and non-public schools, respectively. The field of study of 53.79% of the participants was experimental sciences and 43.45% were studying in tenth grade. The level of physical health needs of female adolescents in Tabriz was high. The physical health needs of the study samples in public schools were higher than non-public schools, with twelfth-grade students more than other grades (P<0.05). By increasing grade point average (GPA), family income, and consequently more access to the Internet and cell phones, adolescents’ physical health needs decreased (P<0.05).ConclusionAccording to the results, the physical health needs of female adolescents were high and one of the most relevant factors was the economic status. Therefore, it is recommended to plan and take measures to meet adolescents’ health needs through the participation of parents, education officials, and other institutions.

Effect of Certain Dinacharya Measures and Dietary Practices on Quality of Life of Elderly: A Cross Sectional Survey Study

Old age is sensitive period of life that needs extra care, so as to manage many of age related disorders that affect the quality of life of an elderly. As per Ayurveda, Ageing is a natural phenomenon. To achieve the goal of maintaining the health, Dinacharya (daily regimen), which includes certain measures like body massage, head and feet massage, incorporation of milk and ghee in diet due to their rejuvenating effect and many more simple and effective modes. Aims: To assess the effect of certain Dinacharya (daily regimen) and dietary practices on quality of life of elderly Methodology: Cross sectional survey of 100 elderly in age group 60-90yrs residing in and around Delhi NCR was conducted. The data was collected with the help of specially designed questionnaire about practices of daily regimens and EQ-5D-5L questionnaire to assess quality of life. Observations and Results: The study shows that 72 % subjects had poor to average score with respect to EQ 5D scale. Regular adoption of daily regimen in the form of exercise (36 % subjects), intake of milk (46 % subjects) Intake of ghee (13 % subjects), proper sleep (85 % subjects) and body massage with oil (39 % subjects) and head massage with oil (39 % subjects) is moderate. Conclusion: Old age being a vulnerable period of life, healthy regimen should be adopted as early as possible to experience less morbidity during old age. Extensive adaptation of daily regimen as mentioned in Ayurveda is needed to reduce the health care burden causes due to geriatric dependency.

Risk factors for non-specific neck pain in young adults. A systematic review

BackgroundYoung adulthood is a sensitive period of life where development of musculoskeletal neck pain may be established and impact future health. The objective of this systematic review was to investigate risk factors for non-specific neck pain in young adults.MethodsSystematic searches were conducted in six databases in September 2019. Prospective cohorts and registry studies including participants in whom the risk factor or the outcome (neck pain) was registered in the ages 18–29 years old were included. The Quality in Prognosis Studies tool was used for quality assessment. A modification of the Grading of Recommendations Assessments, Development and Evaluation was used to assess the overall quality of the evidence. Potential risk factors investigated in more than one study were summarised.ResultsSearches yielded 4527 articles, of which six matched the eligibility criteria. Fifty-six potential risk factors were investigated in the six studies, covering a broad range of domains. Five risk factors were investigated in more than one study (female sex, body mass index (BMI), physical activity, duration of computer use and perceived stress). Physical activity and BMI showed no association with neck pain, and inconsistent results were found for female sex, duration of daily computer use and perceived stress. Risk of bias was moderate or high in all studies, and the overall quality of evidence was very low.ConclusionThe studies included many potential risk factors, but none of them showed consistent associations with neck pain. There is a paucity of high-quality studies investigating risk factors for neck pain in young adults.

Neuroprotective Effects of Choline and Other Methyl Donors.

Recent evidence suggests that physical and mental health are influenced by an intricate interaction between genes and environment. Environmental factors have been shown to modulate neuronal gene expression and function by epigenetic mechanisms. Exposure to these factors including nutrients during sensitive periods of life could program brain development and have long-lasting effects on mental health. Studies have shown that early nutritional intervention that includes methyl-donors improves cognitive functions throughout life. Choline is a micronutrient and a methyl donor that is required for normal brain growth and development. It plays a pivotal role in maintaining structural and functional integrity of cellular membranes. It also regulates cholinergic signaling in the brain via the synthesis of acetylcholine. Via its metabolites, it participates in pathways that regulate methylation of genes related to memory and cognitive functions at different stages of development. Choline-related functions have been dysregulated in some neurodegenerative diseases suggesting choline role in influencing mental health across the lifespan.

Stress and Depressive Symptoms Among Demographically Diverse American Pregnant Women

Pregnancy is a sensitive period of life where mental health is of utmost importance to the mother’s and child’s well-being peripartum and beyond. To better prevent and treat common mental health conditions such as depressive symptoms and perceived stress (defined in this study to encompass psychological and physiological (heart rate variability (HRV)) dimensions), it is crucial to examine and report differences in mental health outcomes among demographically diverse pregnant women. Therefore, the purpose of this secondary analysis (N = 79) was to determine if there are differences in mental health outcomes between pregnant women who differ across demographic factors, as well as to determine if demographic factors predict mental health outcomes when controlling for other demographic variables. Findings indicate that there were significant differences in depressive symptoms and perceived stress by all demographic factors except age. Marital status and total household income were the only significant predictors of depressive symptoms and perceived stress, respectively, when all other factors were controlled. There were no significant differences or correlations between demographic variables and HRV. Pregnant women may be predisposed to adverse mental health outcomes, illustrating the need for more refined interventions that are sensitive to pre-existing factors.

A Study of Spirituality in Relationship with Perceived Happiness Status, Perceived Health Status and Academic Achievement among Adolescents

Adolescence is a sensitive period of life which is accompanied by a series of biological, psychological, and cognitive changes in an individual. This age of confusion and immaturity predisposes individuals towards risky behaviour like alcohol/drug abuse, violence, sexual experimentation etc. The Mental Health Foundation (2009) enlisted various protective factors for adolescents that can help in keeping them safe from risky behaviour. These were: spirituality, social support, parental support, meaningful relationships, constructive hobbies etc. Spirituality is a relationship of an individual with the Divine, with oneself and with others. Houston and Cartwright (2007) defined spirituality using four components. The first was a belief in transcendence, something higher than oneself. The second was interconnectedness, which meant the sense of unification with all living beings. The third component was a feeling of love and compassion for others. Fourth component included a sense of purpose and meaning in life. Spirituality has been consistently linked with happiness, better health outcomes and general feelings of wellbeing among adolescents. The present study aimed to investigate the relationship of spirituality with perceived happiness status, perceived health status, and academic achievement among adolescents. A sample of 100 adolescents (50 males and 50 females) in the age range of 16 and 18 years was included in the study. Inter correlation Analysis was conducted to find the relationship between the variables. In order to find out differences between two groups viz. males and females, t tests were employed. Results showed a significant relationship between spirituality, perceived happiness status and academic achievement of adolescents. This study highlighted the importance of spirituality, and how it can be meaningful not only in the emotional and psychological domain, but the cognitive domain as well.

Methylxanthines induce structural and functional alterations of the cardiac system in zebrafish embryos

BackgroundZebrafish embryos are emerging as a model for pharmacological and toxicological studies. We used zebrafish embryos to study the general toxicity and cardiovascular effects of eight methylxanthines: aminophylline, caffeine, diprophylline, doxofylline, etophylline, 3-isobutyl-1-methylxanthine (IBMX), pentoxifylline and theophylline.MethodsMicroinjections of the eight methylxanthines were performed in 1-2 cell stage zebrafish embryos and the general toxicity and cardiovascular effects were analyzed at different time points. Embryotoxicity and teratogenicity were evaluated to understand the general toxicity of these compounds. Structural and functional alterations of the heart were evaluated to assess the cardiovascular effects.ResultsOur results showed different activity patterns of the methylxanthines drugs. Caffeine, IBMX, pentoxifylline and theophylline were highly embryotoxic and teratogenic; aminophylline, doxofylline and etophylline were embryotoxic and teratogenic only at higher doses, and diprophylline showed a minimal (<10%) embryotoxicity and teratogenicity. Most of these drugs induced structural alteration of the heart in 20-40% of the injected embryos with the maximum dose. This structural alteration was fatal with the embryos ultimately dying within 120 hpf. All the drugs induced a transient increase in heart rate at 48 hpf which returned to baseline within 96 hpf. This functional effect of methylxanthines showed similarity to the studies done in humans and other vertebrates.ConclusionOur results indicate the potential toxicity and teratogenicity of different methylxanthines in the embryos during embryonic development, the most sensitive period of life. Although interspecies differences need to be considered before drawing any conclusion, our study elucidated that a single exposure of methylxanthines at therapeutic range could induce cardiac dysfunction besides causing embryotoxicity and teratogenicity. Of all the drugs, diprophylline appeared to be safer, with lower degree of embryotoxicity, teratogenicity and cardiac toxicity as compared to other methylxanthines.

Urinary phthalate metabolites over the first 15 months of life and risk assessment – CHECK cohort study

Phthalates are important group of endocrine disruptors. Infants and young children are susceptible to phthalate exposure. However, information on the phthalate exposure during the early stages of life is very limited. This study was conducted to understand the temporal trend of exposure to major phthalates among infants of Korea during the first 15months after birth, and to estimate associated risks. A total of 286 urine samples were collected from 171 children at 3, 9, 12, or 15months of age, with 77 children sampled for two or more times. Four phthalates, i.e., di(2-ethylhexyl) phthalate (DEHP), di-isobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and diethyl phthalate (DEP) were chosen, and their major metabolites were analyzed in the urine. The DEHP metabolites were detected in 100% of the urine samples at relatively higher levels compared to those reported in other countries. The levels of mono-ethyl phthalate (MEP) were generally lower. Urinary concentrations of most phthalate metabolites, especially DEHP metabolites, increased as children grew older. Intra-class correlation coefficients (ICCs) calculated for DEHP metabolites over time were high (0.7–0.8), suggesting persistence of consistent exposure sources during this sensitive period of life. Hazard quotient (HQ) and hazard index (HI) were calculated from daily intake estimates divided by recommended toxicity thresholds. Among the study population, 4, 16, and 26% of the children showed HI >1 at 9, 12, and 15months of age, respectively. DEHP exposure explained most of the risk estimates. Considering vulnerability of young children to endocrine disruption, efforts to identify sources of exposure and to develop appropriate mitigation options are warranted.

Management Challenges in Adolescents with Crohn?s Disease-Current Practice

The incidence and prevalence of Crohn's disease (CD) in adolescents is rising. The clinical course differs in several aspects from that of adults. Pediatric-onset disease is more extensive and its course is somewhat more aggressive. In addition to the common manifestation of CD, adolescents with CD may present with pubertal delay, growth retardation and osteopenia. These unique aspects of adolescence CD should impact the treatment paradigm. In cases of growth impairment and osteopenia, treatment should be intensive aiming at promoting complete mucosal healing and, in turn, improved growth and bone formation. The use of enteral nutrition should be thus encouraged both for induction and maintenance of remission. However, adolescent CD carries implications that go beyond the physical manifestations of the disease. Children diagnosed with IBD are at increased risk of emotional distress and decreased social functioning. The use of support groups and other psychosocial interventions is advocated as a mean to enhance coping skills and improve quality of life. As many as half of adolescents are non-compliant with the recommended treatment hence, a particular emphasis should be placed on engaging the adolescent in the treatment plan, using several intervention strategies. Adolescence is a time of dynamic physical changes and growth along with emotional maturation. This review highlights some of the unique aspects that should come into play while managing CD during this sensitive period of life.

Dissecting Long-Term Glucose Metabolism Identifies New Susceptibility Period for Metabolic Dysfunction in Aged Mice.

Metabolic disorders, like diabetes and obesity, are pathogenic outcomes of imbalance in glucose metabolism. Nutrient excess and mitochondrial imbalance are implicated in dysfunctional glucose metabolism with age. We used conplastic mouse strains with defined mitochondrial DNA (mtDNA) mutations on a common nuclear genomic background, and administered a high-fat diet up to 18 months of age. The conplastic mouse strain B6-mtFVB, with a mutation in the mt-Atp8 gene, conferred β-cell dysfunction and impaired glucose tolerance after high-fat diet. To our surprise, despite of this functional deficit, blood glucose levels adapted to perturbations with age. Blood glucose levels were particularly sensitive to perturbations at the early age of 3 to 6 months. Overall the dynamics consisted of a peak between 3–6 months followed by adaptation by 12 months of age. With the help of mathematical modeling we delineate how body weight, insulin and leptin regulate this non-linear blood glucose dynamics. The model predicted a second rise in glucose between 15 and 21 months, which could be experimentally confirmed as a secondary peak. We therefore hypothesize that these two peaks correspond to two sensitive periods of life, where perturbations to the basal metabolism can mark the system for vulnerability to pathologies at later age. Further mathematical modeling may perspectively allow the design of targeted periods for therapeutic interventions and could predict effects on weight loss and insulin levels under conditions of pre-diabetic obesity.

Neuronal analysis and behaviour in prenatally gamma-irradiated rats.

The intrauterinal development in mammals represents a very sensitive period of life in relation to many environmental factors, including ionizing radiation (IR). The developing nervous system is particularly vulnerable to IR, and the consequences of exposure are of importance because of its potential health risks. The aim of our work was to assess whether prenatal irradiation of rats on the 17th day of embryonic development with a dose of 1 Gy would affect the formation of new cells and the number of mature neurons in the hippocampus and the selected forms of behaviour in the postnatal period. Male progeny of irradiated and control females was tested at ages of 3 weeks, 2 and 3 months. The number of mitotically active cells in the gyrus dentatus (GD) of the hippocampus was significantly reduced in irradiated rats aged 3 weeks. In irradiated rats aged 2 months, a significant reduction of mature neurons in CA1 area and in GD of the hippocampus was observed. The IR negatively influenced the spatial memory in Morris water maze, significantly decreased the exploratory behaviour and increased the anxiety-like behaviour in elevated plus-maze in rats aged 2 months. No significant differences were observed in animals aged 3 months compared with controls of the same age. A significant correlation between the number of mature neurons in the hilus and of the cognitive performances was found. Our results show that a low dose of radiation applied during the sensitive phase of brain development can influence the level of neurogenesis in the subgranular zone of GD and cause an impairment of the postnatal development of mental functions.

Long-term changes in cognitive bias and coping response as a result of chronic unpredictable stress during adolescence

Animals that experience adverse events in early life often have life-long changes to their physiology and behavior. Long-term effects of stress during early life have been studied extensively, but less attention has been given to the consequences of negative experiences solely during the adolescent phase. Adolescence is a particularly sensitive period of life when regulation of the glucocorticoid “stress” hormone response matures and specific regions in the brain undergo considerable change. Aversive experiences during this time might, therefore, be expected to generate long-term consequences for the adult phenotype. Here we investigated the long-term effects of exposure to chronic unpredictable stress during adolescence on adult decision-making, coping response, cognitive bias, and exploratory behavior in rats. Rats exposed to chronic unpredictable stress (e.g., isolation, crowding, cage tilt) were compared to control animals that were maintained in standard, predictable conditions throughout development. Unpredictable stress during adolescence resulted in a suite of long-term behavioral and cognitive changes including a negative cognitive bias [F(1, 12) = 5.000, P < 0.05], altered coping response [T(1, 14) = 2.216, P = 0.04], and accelerated decision-making [T(1, 14) = 3.245, P = 0.01]. Exposure to chronic stress during adolescence also caused a short-term increase in boldness behaviors; in a novel object test 15 days after the last stressor, animals exposed to chronic unpredictable stress had decreased latencies to leave a familiar shelter and approach a novel object [T(1, 14) = 2.240, P = 0.04; T(1, 14) = 2.419, P = 0.03, respectively]. The results showed that stress during adolescence has long-term impacts on behavior and cognition that affect the interpretation of ambiguous stimuli, behavioral response to adverse events, and how animals make decisions.

Cannabinoid-Opioid Interactions in Drug Discrimination and Self-Administration: Effect of Maternal, Postnatal, Adolescent and Adult Exposure to the Drugs

Cannabinoids and opioids are known to strictly interact in many physiological and pathological functions, including addiction. The endogenous opioid system is significantly influenced by maternal or perinatal cannabinoid exposure, major changes concerning operant behaviour in adult animals. Copious data suggests that adolescence is also a particularly sensitive period of life not only for the initiation of abusing illicit drugs, but also for the effects that these drugs exert on the neural circuitries leading to drug dependence. This paper examines the role played by the age of drug exposure in the susceptibility to discriminative and reinforcing effects of both cannabinoids and opioids. We first revisited evidence of alterations in the density and functionality of mu-opioid and CB1 cannabinoid receptors in reward-related brain regions caused by either maternal, postnatal, adolescent or adult exposure to opioids and cannabinoids. Then, we reviewed behavioural evidence of the long-term consequences of exposure to opioids and cannabinoids during gestation, postnatal period, adolescence or adulthood, focusing mostly on drug discrimination and self-administration studies. Overall, evidence confirms a neurobiological convergence of the cannabinoid and opioid systems that is manifest at both receptor and behavioural levels. Although discrepant results have been reported, some data support the gateway hypothesis that adolescent cannabis exposure contributes to greater opioid intake in adulthood. However, it should be kept into consideration that in humans genetic, environmental, and social factors could influence the direct neurobiological effects of early cannabis exposure to the progression to adult drug abuse.

Critical developmental periods of increased plasticity program ritualized behavior

The consideration of humans going through sensitive periods of life, such as childhood and the early postpartum, may be helpful in understanding the cognitive and evolutionary puzzle of human rituals. During such periods, certain brain systems may mediate an increased susceptibility to learn new behaviors, rational or irrational.