Serum NGF, BDNF and IL-6 levels in postpartum mothers as predictors of infant development: the influence of affective disorders

Twendee X, a mixed antioxidant supplement, improves cognitive function, coordination, and neurotrophic factor expression in long-term vitamin E-deficient mice

Oxidation products gradually accumulate during senescence, enhancing the risk of onset of many severe diseases. One such disease is dementia, and the number of cases of dementia, including Alzheimer's disease, has been increasing world-wide. These diseases can be prevented via attenuation of age-related physiological dysfunction; one preventive approach is the ingestion of antioxidants such as vitamin C and vitamin E. Many antioxidants are readily available commercially. Ingestion of mixed antioxidants is expected to provide further beneficial effects for human health. In this study, we used vitamin E-deficient mice as an animal model of increased oxidative stress and assessed the effects of dosing with mixed antioxidants. Administration of a commercial mixed antioxidant formula, Twendee X significantly improved cognitive function and coordination compared to untreated vitamin E-deficient animals. Furthermore, the levels of brain-derived neurotrophic factor and nerve growth factor were significantly increased in the cerebral cortex of Twendee X-dosed vitamin E-deficient mice compared to untreated animals. These results indicate that intake of a mixed antioxidant supplement may be beneficial to human health, even after oxidative stress has begun. In the next stage, it will be necessary to compare with other antioxidants and consider whether it is effective in the aged model.

Prenatal and postpartum maternal mental health and neonatal motor outcomes during the COVID-19 pandemic

Background

Rates of prenatal and postpartum stress and depression in pregnant individuals have increased during the COVID-19 pandemic. Perinatal maternal mental health has been linked to worse motor development in offspring, with motor deficits appearing in infancy and early childhood. We aimed to evaluate the relationship between prenatal and postpartum stress and depression and motor outcome in infants born during the COVID-19 pandemic.

Methods

One hundred and seventeen participants completed an online prospective survey study at two timepoints: during pregnancy and within 2 months postpartum. Depression was self-reported using the Edinburgh Perinatal/Postpartum Depression Scale (EPDS), and stress via the Perceived Stress Scale (PSS). Mothers reported total infant motor ability (fine and gross) using the interRAI 0–3 Developmental Domains questionnaire.

Results

Prenatal (EPDS median=10.0, interquartile range[IQR]=6.0 – 14.0, B=-0.035, 95%CI=-0.062 to -0.007, p = 0.014) and postpartum maternal depression outcomes (median=7, IQR=4–12, B=-0.037, 95%CI= -0.066 to -0.008, p = 0.012) were significantlynegatively associated with total infant motor ability. Neither pregnancy nor postpartum perceived stress was associated with infant motor function. A cluster analysis revealed that preterm and low-birth weight infants whose mothers reported elevated depressive symptoms during pregnancy and in the postpartum period had the poorest motor outcomes.

Conclusions

Prenatal and postpartum depression, but not stress, was associated with early infant motor abilities. Preterm and low-birth weight infants whose mothers reported elevated depressive symptoms maybe at-risk of experiencing poor motor outcomes. These results highlight the importance of identifying pre- and postnatal maternal mental health issues, especially during the ongoing COVID-19 pandemic.

Association Between Maternal Perinatal Depression and Anxiety and Child and Adolescent Development: A Meta-analysis

IMPORTANCE

There is widespread interest in associations between maternal perinatal depression and anxiety and offspring development; however, to date, there has been no systematic, meta-analytic review on the long-term developmental outcomes spanning infancy through adolescence.

OBJECTIVE

To provide a comprehensive systematic review and meta-analysis of the extant literature on associations between maternal perinatal depression and anxiety and social-emotional, cognitive, language, motor, and adaptability outcomes in offspring during the first 18 years of life.

DATA SOURCES

Six databases were searched (CINAHL Complete, Cochrane Library, Embase, Informit, MEDLINE Complete, and PsycInfo) for all extant studies reporting associations between perinatal maternal mental health problems and offspring development to March 1, 2020.

STUDY SELECTION

Studies were included if they were published in English; had a human sample, quantitative data, a longitudinal design, and measures of perinatal depression and/or anxiety and social-emotional, cognitive, language, motor, and/or adaptability development in offspring; and investigated an association between perinatal depression or anxiety and childhood development.

DATA EXTRACTION AND SYNTHESIS

Of 27 212 articles identified, 191 were eligible for meta-analysis. Data were extracted by multiple independent observers and pooled using a fixed- or a random-effects model. A series of meta-regressions were also conducted. Data were analyzed from January 1, 2019, to March 15, 2020.

MAIN OUTCOMES AND MEASURES

Primary outcomes included social-emotional, cognitive, language, motor, and adaptability development in offspring during the first 18 years of life.

RESULTS

After screening, 191 unique studies were eligible for meta-analysis, with a combined sample of 195 751 unique mother-child dyads. Maternal perinatal depression and anxiety were associated with poorer offspring social-emotional (antenatal period, r = 0.21 [95% CI, 0.16-0.27]; postnatal period, r = 0.24 [95% CI, 0.19-0.28]), cognitive (antenatal period, r = -0.12 [95% CI, -0.19 to -0.05]; postnatal period, r = -0.25 [95% CI, -0.39 to -0.09]), language (antenatal period, r = -0.11 [95% CI, -0.20 to 0.02]; postnatal period, r = -0.22 [95% CI, -0.40 to 0.03]), motor (antenatal period, r = -0.07 [95% CI, -0.18 to 0.03]; postnatal period, r = -0.07 [95% CI, -0.16 to 0.03]), and adaptive behavior (antenatal period, r = -0.26 [95% CI, -0.39 to -0.12]) development. Findings extended beyond infancy, into childhood and adolescence. Meta-regressions confirmed the robustness of the results.

CONCLUSIONS AND RELEVANCE

Evidence suggests that perinatal depression and anxiety in mothers are adversely associated with offspring development and therefore are important targets for prevention and early intervention to support mothers transitioning into parenthood and the health and well-being of next-generation offspring.

Maternal perinatal mental health and infant and toddler neurodevelopment - Evidence from low and middle-income countries. A systematic review

BACKGROUND

There is extensive lack of awareness of maternal mental health and its impact on child development in low- and middle-income countries (LAMICs). The aim of this systematic review was to analyze evidence for various maternal perinatal mental health disorders and their association with different domains of infant and toddler neurodevelopment during the first two postnatal years in LAMICs.

METHODS

A comprehensive literature search was conducted within six databases from Jan 1990-April 2019. All included studies were narratively synthesized.

RESULTS

Twenty-four studies, nine cross sectional and 15 longitudinal cohort studies, were included. Three studies were conducted in low-income, 11 in lower-middle-income and ten in upper-middle-income countries. The majority of studies assessed maternal mental health postnatally and 14 of these 22 studies found a significant association with infant and toddler neurodevelopment. Five of the ten studies reporting on exposure to prenatal mental health found a significant association. The most common maternal mental health disorder studied was depression, while the main neurodevelopmental outcomes assessed were motor, cognitive and language development.

LIMITATIONS

Meta-analysis could not be conducted due to the variability in the reported maternal mental health disorders and the different times of assessment of exposures and outcomes.

CONCLUSIONS

Maternal perinatal mental health disorders and their association with different domains of neurodevelopment in LAMICs is still inconclusive due to a limited number of papers. Mother-infant dyads in LAMICs are exposed to multiple and cumulative risk factors and causal pathways between maternal mental health and infant neurodevelopment are still poorly understood.

Postpartum stress and infant outcome: A review of current literature

Postpartum stress has been shown to have an association with infant growth, nutrition, bonding, temperament and ultimately childhood mental wellbeing. When persistent, recurring or chronic, it can negatively impact infant outcome, including the subscales of mental wellbeing such as growth, development, feeding, attachment and sleep. This study aims to define the physical and functional effect of postpartum stress on measures of infant mental wellbeing. A systematic review of English language articles published between 1995 and 2019 on PubMed, Medline and Psych base databases was carried out. Search terms used included postpartum, stress, infant, growth, development, nutrition, attachment and sleep. Both qualitative and quantitative studies were reviewed with eligibility criteria. Inclusion criteria of human studies, mothers diagnosed with depressive and anxiety symptoms postpartum with infant correlates were used. All animal studies and studies with women already on medication were excluded. A total of 74 articles were reviewed and summarized into postpartum stress associations with infant growth, development, nutrition, sleep and maternal fetal attachment. Postpartum stress is negatively associated with poor developmental trajectories and linear growth deficits, causing stunting in growth; poor language and cognitive development; poor gross and fine motor movement, and infant sleep. An inverse relationship exists with breast feeding and postpartum depression. More importantly, breastfeeding efficacy is important for sustaining positive infant feeding outcome. Increased maternal age during postpartum depression has been linked, as a contributing factor, to decreased maternal fetal attachment/bonding. A ripple effect exists from the association between postpartum stress and poor infant sleep. There is strong evidence that correlates PPS to infant outcome, mediated through many external factors. More research needs to be conducted to delineate and potentially mitigate the impact of modifiable factors. Not all articles in the literature were reviewed.

Role of neurotrophins in pregnancy, delivery and postpartum

Neurotrophins (NTs) are a family of polypeptides whose functions have been extensively studied in the past two decades. In particular, Nerve Growth Factor (NGF) and Brain-Derived Neurotrophic Factor (BDNF) play a major role in the development, nutrition and growth of the central and peripheral nervous system and in the pathogenesis of neurodegenerative, cardiometabolic and (auto)immune diseases. However, NGF and BDNF have subtle functions for follicular development, implantation, and placentation. This short narrative review summarizes the existing evidence, published between 2000 and 2019, about the role of NTs in many different conditions that might affect women during and after pregnancy such as preeclampsia, gestational diabetes, obesity, depression, anxiety, smoking and alcohol abuse. Literature suggests that the dysregulation of synthesis and release of NTs may lead to decisive effects on both maternal and fetal health. Some piece of evidences was found about a possible association between NGF/BDNF and breastfeeding. Additional studies on human models are necessary to further characterize the role of NTs in life-changing experiences like labor and delivery.

Prenatal Glucocorticoid Treatment Completeness and Steroid Hormonal Levels as Related to Infant and Maternal Health

This study was conducted to confirm the negative associations between testosterone and cortisol levels and health and developmental outcomes in very low-birth weight (VLBW) infants after controlling for prenatal glucocorticoid (GC) treatment. Seventy-four VLBW infant-mother pairs were recruited from a neonatal intensive care unit in the Southeastern United States. We divided the pairs into the complete (n = 58) and incomplete (n = 16) GC treatment groups. Data on infants and mothers were obtained at birth, 40 weeks' postmenstrual age, and 3 and 6 months' corrected age. Salivary testosterone and cortisol levels of the pairs were determined at 40 weeks' postmenstrual age using enzyme immunoassay. Log-linear and general linear mixed models showed that gestational age and birth weight were lower when testosterone was 1 pg/mL higher. When cortisol was 1 μg/dL higher, technology dependence at discharge was higher and motor development at 6 months was lower. Mothers with complete GC treatment had greater parity and gravida, more prenatal visits, and more medical complications. The study outcomes supported our hypothesis that steroid hormonal levels are more predictive of infant health and development than GC treatment completeness. Single dose of GC treatment might be just as effective as 2 doses, although further study with more subjects would be needed to confirm. As the associations with steroid hormonal levels lasted longer than the GC treatment associations, we recommend confirming the predictive effects of testosterone and cortisol levels after 6 months.

Natural sunlight plus vitamin D supplementation ameliorate delayed early motor development in newborn infants from maternal perinatal depression

BACKGROUND

Increased cortisol has been shown to be negatively correlated with infant motor development. Sunlight help decrease the level of cortisol. Vitamin D is associated with infant motor development. The present study aimed to determine whether natural sunlight exposure plus vitamin D supplements could ameliorate delayed early motor development in little infants from maternal perinatal depression.

METHODS

The term pregnant women waiting for delivery from the department of gynecology and obstetrics were assessed depressive symptoms by Hamilton Rating Scale for Depression (HAMD). 120 normal and 229 depressed subjects were recruited. During 2 days postpartum, infant motor development were assessed by Neonatal Behavioral Assessment Scale (NBAS). Infants of 2-day-old in maternal depression group were divided into four groups: control group, conventional vitamin D supplements (400IU/d) group, high dose of vitamin D supplements group (1000IU/d), sunlight plus conventional vitamin D supplement group (400IU/d). Serum and hair cortisol (HairF) in mothers and infants were measured.

RESULTS

The infants of perinatal depressed mothers displayed early motor developmental delay accompanied by increased cortisol. Sunlight plus conventional vitamin D supplement (400IU/d) were better than exclusive vitamin D supplements for the amelioration delayed early motor development in infants (p < 0.05). The infants exposure to sunlight 7-14 h/week plus conventional vitamin D supplement reached the best scores of motor development and the lowest HairF (p < 0.05).

LIMITATIONS

We should have measured the serum 25OH-vitamin D concentrations.

CONCLUSIONS

Sunlight plus vitamin D supplements could ameliorate delayed early motor development in little infants by decreasing cortisol from perinatal depression.

Serum NGF levels may be associated with intrauterine antiepileptic exposure-related developmental problems

OBJECTIVE

It has been shown that maternal epilepsy and antiepileptic drug use during pregnancy have adverse developmental outcomes in children. The aim of this study was to investigate the developmental outcomes of maternal epilepsy and prenatal antiepileptic exposure. We also looked for the associations between serum levels of glial cell-derived neurotrophic factor (GDNF) and nerve growth factor (NGF) and developmental outcomes.

METHODS

This is a retrospective, nonrandomized, case-controlled study. Fifty-three children aged two to six years old with maternal epilepsy were included in the case group. Fifty-three age- and gender-matched children without maternal epilepsy were included in the control group. Developmental assessment was conducted using the Denver II Developmental Screening Test (DDST-II). Serum levels of NGF and GDNF were measured using an enzyme-linked immunosorbent assay (ELISA) kit.

RESULTS

Multiple regression analysis revealed that prenatal antiepileptic exposure was significantly associated with lower global developmental scores (B = -7.5, confidence interval (CI): -13.1; -1.9, p = 0.009) while periconceptional folate use was associated with a reduced risk for adverse developmental outcomes (B = 6.6, CI: 0.91; 12.3, p = 0.024). Children with prenatal antiepileptic exposure are at increased risk for global developmental delay (GDD) particularly for language domain (p = 0.018). We found a statistically significant positive correlation between NGF levels and global developmental scores (r = 0.302, p = 0.009). Serum levels of GDNF in children with maternal epilepsy were significantly lower than the children without maternal epilepsy (p = 0.025).

CONCLUSIONS

Prenatal antiepileptic exposure was related with the increased risk of GDD while periconceptional folate use was related with lower risk. Clinicians should inform all women in reproductive age with epilepsy about the possible benefits and risks of antiepileptic drug use during a possible pregnancy. Periconceptional folate use has protective effect on child development, and all women on antiepileptic drugs should be encouraged for periconceptional folate use. Serum NGF levels may be a promising biomarker for monitoring global development delay in at-risk population.

Impact of Postpartum Mental Illness Upon Infant Development

PURPOSE OF REVIEW

This review evaluates the state of the research regarding the effects of postpartum mental illness on the developing infant. It defines the scope of these disorders in the literature, and includes the impact of disorders referred to as perinatal mood and anxiety disorders (PMADs) on infants.

RECENT FINDINGS

New research reveals that PMADs apply to not only mothers, but that fathers can also experience perinatal depression and anxiety. When untreated in a primary caregiver, PMADs adversely affect parental cognitions and beliefs, attachment to the infant, and the growing caregiver-infant relationship. PMADs affect early developmental outcomes of infants including neurosynaptic development, regulatory development, and developmental milestones. Early identification and treatment for PMADs are critical to ensure optimal infant development. Standardized and routine screening for PMADs, especially in the first 6 months postpartum, and cross-disciplinary communication among medical providers afford the best opportunity for early identification and treatment.

Associations Between Hormonal Biomarkers and Cognitive, Motor, and Language Developmental Status in Very Low Birth Weight Infants

BACKGROUND

Male infants are more prone to health problems and developmental delays than female infants.

OBJECTIVES

On the basis of theories of gender differences in brain development and social relationships, we explored associations between testosterone and cortisol levels with infant cognitive, motor, and language development ("infant development") in very low birth weight (VLBW) infants, controlling for mother-infant interactions, characteristics of mothers and infants, and days of saliva collection after birth.

METHODS

A total of 62 mother-VLBW infant pairs were recruited from the newborn intensive care unit of a tertiary medical center in the Southeast United States. Data were collected through infant medical record review, biochemical measurement, observation of mother-infant interactions, and standard questionnaires. Infant development was assessed at 6 months corrected age (CA), and mother-infant interactions were observed at 3 and 6 months CA.

RESULTS

General linear regression with separate analyses for each infant gender showed that high testosterone levels were positively associated with language development of male infants after controlling for mother-infant interactions and other covariates, whereas high cortisol levels were negatively associated with motor development of female infants after controlling for mother-infant interactions.

CONCLUSIONS

Steroid hormonal levels may well be more fundamental factors for assessing infant development than infant gender or mother-infant interactions at 6 months CA.

Identifying women at risk for sustained postpartum anxiety

INTRODUCTION

To describe the prevalence of sustained postpartum anxiety and to develop a multifactorial predictive model to assist in targeted screening procedures.

METHODS

In a population-based cohort in a health region near Vancouver, Canada, 522 mothers completed a mailed questionnaire at 1, 4, and 8 weeks postpartum measuring socio-demographic, biological, pregnancy-related, life stressor, social support, obstetric, and maternal adjustment factors. We undertook a sequential logistic regression analysis to develop a multifactorial predictive model of sustained postpartum anxiety, as measured by a State Trait Anxiety Inventory (STAI) score >40 at 1 week and/or 4 weeks, and 8 weeks postpartum.

RESULTS

The prevalence of sustained postpartum anxiety was 12.6% (95% CI 9.6-16.2). In the multivariable model, predictors of sustained anxiety in the postpartum period were perceived stress at 1 week (1 SD increase; aOR 3.74, 95% CI 2.17-6.44) and partner social support at 1 week (1 SD increase; aOR 0.59, 95% CI 0.40-0.85). Depression symptomatology at 1 week, child care stress, and maternal self-esteem were non-significant.

LIMITATIONS

Single women and women from ethnic minority backgrounds were underrepresented in the sample.

CONCLUSIONS

A large proportion of women experience sustained postpartum anxiety. High perceived stress and low partner social support can be used to facilitate early identification of women likely to experience persistent anxiety in the postpartum period and suggest the need for urgent access to psychotherapeutic services for these women. These factors may also be potential targets for individual or couples therapy to treat postpartum anxiety.

Effects of anticipated neonatal surgical intervention on maternal milk cytokine production

BACKGROUND

Maternal stress on neonatal outcomes of infants admitted to the NICU is incompletely understood. We previously demonstrated breast milk derived cytokines remain biologically active in the neonatal intestine. We hypothesized that the need for neonatal surgical intervention would be stimulus leading to maternal cytokine production thus affecting neonatal outcome.

METHODS

Discarded expressed breast milk (EBM) in the first 3weeks following delivery was analyzed for IL-23 and IL-10 by ELISA. Variables analyzed included: the need for a pediatric surgical procedure, the need for cardiac surgical procedure, no surgical interventions, and survival. All values are expressed as mean±SEM. Statistical analysis utilized Kruskal and Mann-Whitney test.

RESULTS

EBM from mothers whose infants required any surgical procedure (n=19) revealed significant elevation in IL-10 but not IL-23 compared to nonsurgical EBM (n=18). Subdivided by procedure type, there was no difference between those undergoing a cardiac (n=9) versus pediatric surgical (n=10) procedure in both IL-10 and IL-23. Mothers whose infants requiring surgical intervention or whose infants did not survive in the first 3weeks of life had elevation of IL-10.

CONCLUSION

Results suggest maternal stress impacts the cytokine profile of breast milk.

LEVEL OF EVIDENCE

Level III.

Serum brain-derived neurotrophic factor (BDNF) across pregnancy and postpartum: Associations with race, depressive symptoms, and low birth weight

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is implicated as a causal factor in major depression and is critical to placental development during pregnancy. Longitudinal data on BDNF across the perinatal period are lacking. These data are of interest given the potential implications for maternal mood and fetal growth, particularly among Black women who show ∼2-fold greater risk for delivering low birth weight infants.

METHODS

Serum BDNF, serum cortisol, and depressive symptoms (per CES-D) were assessed during each trimester and 4-11 weeks postpartum among 139 women (77 Black, 62 White). Low birth weight (<2500g) was determined via medical record.

RESULTS

Serum BDNF declined considerably from 1st through 3rd trimesters (ps≤0.008) and subsequently increased at postpartum (p<0.001). Black women exhibited significantly higher serum BDNF during the 1st trimester, 2nd trimester, and postpartum (ps≤0.032) as well as lower serum cortisol during the 2nd and 3rd trimester (ps≤0.01). Higher serum cortisol was concurrently associated with lower serum BDNF in the 2nd trimester only (p<0.05). Controlling for race, serum BDNF at both the 2nd and 3rd trimester was negatively associated with 3rd trimester depressive symptoms (ps≤0.02). In addition, women delivering low versus healthy weight infants showed significantly lower serum BDNF in the 3rd trimester (p=0.004). Women delivering low versus healthy weight infants did not differ in depressive symptoms at any time point during pregnancy (ps≥0.34).

CONCLUSIONS

Serum BDNF declines considerably across pregnancy in Black and White women, with overall higher levels in Blacks. Lower serum BDNF in late pregnancy corresponds with higher depressive symptoms and risk for low birth weight in Black and White women. However, the predictive value of serum BDNF in pregnancy is specific to within-race comparisons. Potential links between racial differences in serum BDNF and differential pregnancy-related cortisol adaptation require further investigation.

Identifying women at risk for postpartum anxiety: a prospective population-based study

OBJECTIVE

To develop a multifactorial model to predict anxiety symptomatology at 8 weeks postpartum.

METHOD

In a population-based study, 522 women in a health region near Vancouver, Canada, completed questionnaires at 1, 4, and 8 weeks postpartum. Questionnaires included risk factors measured at 1 week (sociodemographic, biological, pregnancy-related, life stressors, social support, obstetric, and maternal adjustment). Sequential logistic regression was completed to develop a predictive model of anxiety symptomatology at 8 weeks (State-Trait Anxiety Inventory score >40).

RESULTS

The prevalence of anxiety symptomatology at 1, 4, and 8 weeks postpartum was 22.6%, 17.2%, and 14.8% respectively. In multivariable models, anxiety symptomatology at 1 week (aOR 2.78, 95% CI: 1.04-7.43), multiparous parity (aOR 3.29, 95% CI: 1.28-8.48), history of psychiatric problems (aOR 3.07, 95% CI: 1.19-7.97), perceived stress (1 SD increase: aOR 4.92, 95% CI: 2.62-9.26), and childcare stress (1 SD increase: aOR 1.63, 95% CI: 1.01-2.64) were independent predictors of anxiety symptomatology at 8 weeks.

CONCLUSION

While a significant proportion of women experience anxiety symptomatology following childbirth, multiparous women with a psychiatric history who have high levels of diverse stress are at greatest risk. These key factors may be used to promote early identification and secondary preventive interventions.

Anxiety disorders in postpartum women: A systematic review and meta-analysis

BACKGROUND

Evidence suggests that postpartum anxiety is relatively common among postpartum women. Anxiety meeting diagnostic criteria for a disorder represents anxiety at its most severe, distressing, and persistent, and thus it is most important to identify, understand, and treat. This paper describes a comprehensive systematic review of anxiety disorders among postpartum women, along with meta-analysis of prevalence.

METHODS

Findings are based on a thorough search of the literature, strict inclusion of only studies which utilized the gold standard of diagnostic interviews for anxiety disorder determination, and critical appraisal and review of included studies. A random effects meta-analysis was used to determine prevalence.

RESULTS

Fifty-eight studies were included in the review: 13 addressed prevalence, 5 incidence, 14 onset, 16 course, 13 correlates and risk factors, 15 outcomes, and 2 treatments for postpartum anxiety disorders. An estimated 8.5% of postpartum mothers experience one or more anxiety disorders.

LIMITATIONS

Many limitations relate to the state of the current literature, including a small number of studies to answer specific research questions for each disorder, methodological limitations, and considerable heterogeneity across studies.

CONCLUSIONS

Anxiety disorders are common among postpartum women. The review summarizes the current status of research on postpartum anxiety disorders and underscores the need for increased research to more accurately determine prevalence, understand course, identify risk factors and outcomes, and determine effective treatments. Greater clinical attention to these disorders is warranted to ameliorate the negative consequences of postpartum anxiety disorders on women and families.

Maternal alterations in the proteome of the medial prefrontal cortex in rat

Proteomic differences between rat dams and control mothers deprived of their pups immediately after delivery were investigated in the medial prefrontal cortex (mPFC). A 2-D DIGE minimal dye technique combined with LC-MS/MS identified 32 different proteins that showed significant changes in expression in the mPFC, of which, 25 were upregulated and 7 were downregulated in dams. The identity of one significantly increased protein, the small heat-shock protein alpha-crystallin B chain (Cryab), was confirmed via Western blot analysis. Alpha-crystallin B chain was distributed in scattered cells in the mPFC, as demonstrated by immunohistochemistry. Furthermore, it was found to be localized in parvalbumin-containing neurons using double labeling. The elevation of its mRNA level in rat dams was also demonstrated via RT-PCR. The functional classification of the altered proteins was conducted using the UniProt and Gene Ontology protein databases. The identified proteins predominantly participate in synaptic transport and plasticity, neuron development, oxidative stress and apoptosis, and cytoskeleton organization. A common regulator and target analysis of these proteins determined using the Elsevier Pathway Studio Platform suggests that protein level changes associated with pup nursing are driven by growth factors and cytokines, while the MAP kinase pathway was identified as a common target. A high proportion of the proteins that were found to be altered in the mPFC are associated with depression.

BIOLOGICAL SIGNIFICANCE

The behavior and emotional state of females change robustly when they become mothers. The brain, which governs these changes, may also undergo molecular alterations in mothers. As no proteomics approaches have been applied regarding maternal changes in the brain, we addressed this issue in the mPFC as this brain area is the uppermost cortical center of maternal control and the associated mood changes. The high number of protein-level alterations found between mothers taking care of their litter and those without pups indicates that pup nursing is associated with cortical protein-level changes. Alterations in proteins participating in synaptic transport, plasticity and neuron development suggest neuroplastic changes in the maternal brain. In turn, the relatively high number of altered proteins in the mPFC associated with depression suggests that the physiological effects of the protein-level alterations in the maternal mPFC could promote the incidence of postpartum depression. Cryab, a protein confirmed to be increased during maternal behaviors, was selectively found in parvalbumin cells, which, as fast-spiking interneurons, are associated with depression. The function of Cryab should be further investigated to establish whether it can be used to identify drug targets for future drug development.