Emotion Reactivity Is Increased 4-6 Weeks Postpartum in Healthy Women: A Longitudinal fMRI Study

Marked endocrine alterations occur after delivery. Most women cope well with these changes, but the postpartum period is associated with an increased risk of depressive episodes. Previous studies of emotion processing have focused on maternal–infant bonding or postpartum depression (PPD), and longitudinal studies of the neural correlates of emotion processing throughout the postpartum period in healthy women are lacking. In this study, 13 women, without signs of post partum depression, underwent fMRI with an emotional face matching task and completed the MADRS-S, STAI-S, and EPDS within 48 h (early postpartum) and 4–6 weeks after delivery (late postpartum). Also, data from a previous study including 15 naturally cycling controls assessed in the luteal and follicular phase of the menstrual cycle was used. Women had lower reactivity in insula, middle frontal gyrus (MFG), and inferior frontal gyrus (IFG) in the early as compared to the late postpartum assessment. Insular reactivity was positively correlated with anxiety in the early postpartum period and with depressive symptoms late postpartum. Reactivity in insula and IFG were greater in postpartum women than in non-pregnant control subjects. Brain reactivity was not correlated with serum estradiol or progesterone levels. Increased reactivity in the insula, IFG, and MFG may reflect normal postpartum adaptation, but correlation with self-rated symptoms of depression and anxiety in these otherwise healthy postpartum women, may also suggest that these changes place susceptible women at increased risk of PPD. These findings contribute to our understanding of the neurobiological aspects of the postpartum period, which might shed light on the mechanisms underlying affective puerperal disorders, such as PPD.     

Associations among within-litter differences in early mothering received and later emotional behaviors,mothering, and cortical tryptophan hydroxylase-2 expression in female laboratory rats

This article is part of a Special Issue “Parental Care”. The effects of differential maternal care received on offspring phenotype in rodents has been extensively studied between litters, but the consequences of differential mothering within litters on offspring neurobehavioral development have been rarely examined. We here investigated how variability in maternal care received among female rat siblings (measured four times daily on postnatal days 4, 6, 8, and 10) relates to the siblings' later emotional and maternal behaviors. As previously reported, we found that some female pups received up to three times more maternal licking bouts compared to their sisters; this difference was positively correlated with the pups' body weights. The number of maternal licking bouts that females received was negatively correlated with their later neophobic behaviors in an open field during periadolescence, but positively correlated with their anxiety-related behavior in an elevated plus maze during adulthood. Licking received was also positively correlated with females' later likelihood to retrieve pups in a maternal sensitization paradigm. In addition, females' neophobia during adolescence and anxiety-related behavior during adulthood predicted some aspects of both postpartum and sensitized maternal responsiveness. Medial prefrontal cortex expression of tryptophan hydroxylase-2 (TPH2; enzyme necessary for serotonin synthesis) was negatively associated with early maternal licking received. Interestingly, cortical TPH2 was positively associated with the maternal responsiveness of sensitized virgins but negatively associated with it in postpartum females. These results indicate that within-litter differences in maternal care received is an often neglected, but important, contributor to individual differences in offspring socioemotional behaviors as well as to the cortical serotonin neurochemistry that may influence these behaviors.     

Postpartum depression: Etiology,treatment and consequences for maternal care

This article is part of a Special Issue “Parental Care”. Pregnancy and postpartum are associated with dramatic alterations in steroid and peptide hormones which alter the mothers' hypothalamic pituitary adrenal (HPA) and hypothalamic pituitary gonadal (HPG) axes. Dysregulations in these endocrine axes are related to mood disorders and as such it should not come as a major surprise that pregnancy and the postpartum period can have profound effects on maternal mood. Indeed, pregnancy and postpartum are associated with an increased risk for developing depressive symptoms in women. Postpartum depression affects approximately 10–15% of women and impairs mother–infant interactions that in turn are important for child development. Maternal attachment, sensitivity and parenting style are essential for a healthy maturation of an infant's social, cognitive and behavioral skills and depressed mothers often display less attachment, sensitivity and more harsh or disrupted parenting behaviors, which may contribute to reports of adverse child outcomes in children of depressed mothers. Here we review, in honor of the “father of motherhood”, Jay Rosenblatt, the literature on postnatal depression in the mother and its effect on mother–infant interactions. We will cover clinical and pre-clinical findings highlighting putative neurobiological mechanisms underlying postpartum depression and how they relate to maternal behaviors and infant outcome. We also review animal models that investigate the neurobiology of maternal mood and disrupted maternal care. In particular, we discuss the implications of endogenous and exogenous manipulations of glucocorticoids on maternal care and mood. Lastly we discuss interventions during gestation and postpartum that may improve maternal symptoms and behavior and thus may alter developmental outcome of the offspring.     

Auditory affective norms for German: testing the influence of depression and anxiety on valence and arousal ratings

Background

The study of emotional speech perception and emotional prosody necessitates stimuli with reliable affective norms. However, ratings may be affected by the participants'' current emotional state as increased anxiety and depression have been shown to yield altered neural responding to emotional stimuli. Therefore, the present study had two aims, first to provide a database of emotional speech stimuli and second to probe the influence of depression and anxiety on the affective ratings.

Methodology/Principal Findings

We selected 120 words from the Leipzig Affective Norms for German database (LANG), which includes visual ratings of positive, negative, and neutral word stimuli. These words were spoken by a male and a female native speaker of German with the respective emotional prosody, creating a total set of 240 auditory emotional stimuli. The recordings were rated again by an independent sample of subjects for valence and arousal, yielding groups of highly arousing negative or positive stimuli and neutral stimuli low in arousal. These ratings were correlated with participants'' emotional state measured with the Depression Anxiety Stress Scales (DASS). Higher depression scores were related to more negative valence of negative and positive, but not neutral words. Anxiety scores correlated with increased arousal and more negative valence of negative words.

Conclusions/Significance

These results underscore the importance of representatively distributed depression and anxiety scores in participants of affective rating studies. The LANG-audition database, which provides well-controlled, short-duration auditory word stimuli for the experimental investigation of emotional speech is available in Supporting Information S1.     

Selenium intake and status of postpartum women and postnatal depression during the first year after childbirth in New Zealand – Mother and Infant Nutrition Investigation (MINI) study

BackgroundSelenium (Se) plays an important role in selenoproteins as an antioxidant, and is involved in thyroid function, mental health and child development. Selenium is low in the local food supplies in NZ. Low selenium intake has been reported in women of childbearing age and postmenopausal women, however, there is little research relating to breastfeeding women and their infants.PurposeThe study investigates maternal and infant selenium intake and status during the first year postpartum, and possible relationships to postnatal depression and anxiety.Basic proceduresThe Mother and Infant Nutrition Investigation (MINI) study is an observational longitudinal cohort study. In total 87 breastfeeding mother-infant pairs were recruited and followed up at 3, 6 and 12 months postpartum. Maternal selenium intake was estimated from a four-day diet diary (4DDD). Selenium concentrations were measured in maternal spot urine, breastmilk and plasma; and infant spot urine samples. Postnatal depression was screened by the Edinburgh Postnatal Depression Scale (EPDS) questionnaire.Main findingsMedian maternal selenium intake was 62 (50, 84) μg/day, with 56 % below the Estimated Average Requirement (EAR) of 65 μg/day. At 3, 6, and 12 months postpartum, median maternal urinary selenium:creatinine ratios were 29.0 (22.4, 42.0), 29.5 (23.1, 28.4), and 30.9 (24.3, 35.3) μg/g; median infant urinary selenium concentrations (IUSC) were 8 (6,13), 11 (6, 15), and 24 (10, 40) μg/L; median breastmilk selenium concentrations (BMSC) were 13 (11, 14), 11 (9, 11) and 12 (11, 13) μg/L; 18 %, 11 % and 14 % of women reported probable minor depression based on the EPDS scores equal or above 10. Estimated median infant selenium intake at 3 and 6 months were 9 (8, 11) and 8 (7, 10) μg/day with 85 % and 93 % below the Adequate Intake of 12 μg/day. Median maternal plasma selenium was 105.8 μg/L at 6 months postpartum. Minor depression at three months postpartum was significantly different across tertiles of plasma selenium concentrations (p = 0.041).Principle conclusionsSuboptimal selenium intake was observed among breastfeeding mothers and their infants in the MINI study. Potentially, some women had insufficient selenium status. Relation between selenium status and risk of postnatal depression and anxiety was inconclusive.Further research is required to explore effects on maternal thyroid function and infant neurodevelopment among women with inadequate selenium intake and status.     

Comparison of the "nursing" and other parental behaviors of nulliparous and lactating female rats

Virgin female rats display maternal behaviors after continuous exposure to pups (sensitization) that are in some respects similar to those of postpartum females. We herein provide a detailed comparison of the "nursing" and other parental behaviors of maternally sensitized virgin females and postpartum lactating dams. Ovariectomized and intact virgin females were exposed to pups until displaying maternal behavior. On the females' fourth day of maternal responsiveness, the pups were removed for 3 h and then returned, and subject-litter interactions were observed for 45 min. Behavior of maternal virgins was compared with that of lactating dams observed on day 4 postpartum interacting with either suckling pups or pups unable to suckle due to perioral anesthesia. Ovariectomy had no effect on behavior of virgins. Retrieval and licking of pups were deficient in virgins compared with lactating dams. Suckled dams showed prolonged kyphosis (upright crouched nursing), whereas nonsuckled dams displayed little kyphosis but rather were often in a hunched position over pups. Some aspects of quiescent "nursing" behaviors of virgins were surprisingly similar to those of suckled dams, including the latency to and duration of quiescence. Nonsuckling pup stimulation elicited more kyphosis in virgins than in lactating dams, which was still much less than in suckled dams. Virgins also "nursed" pups in hunched and prone postures. Differences between sensitized and postpartum females in their maternal behaviors likely reflect differences in motivation as well as sensory inputs they receive from pups. In particular, sensory regulation of "nursing" behaviors is influenced by reproductive state because nonsuckling pups elicit different postural responses in sensitized and lactating mothers.     

House Staff Well-being

From a survey of 281 house-staff members of a university medical center, we found that nearly half the respondents were afraid to complain about their training programs and were concerned that their relationship with their partner would not survive the residency. In all, 40% reported that anxiety or depression impaired their performance for a month or more; 12% reported an increased use of alcohol, marijuana, or cocaine; and 7% an increased use of sedatives, stimulants, or opioids. Stressors and dysfunctional behaviors did not differ significantly between male and female house staff, but many women had more tenuous support systems. Married house staff had stronger support systems and less substance abuse, anxiety, and depression. Departments differed widely in house-staff morale, available social supports, and the frequency of dysfunctional behaviors. Residency program directors should assess their house staff''s distress and study and initiate means to reduce stress, increase support, and facilitate coping.     

Reduced anxiety in postpartum rats requires recent physical interactions with pups, but is independent of suckling and peripheral sources of hormones

Changes in emotional behavior occur across the reproductive cycle in female rodents, with reduced anxiety found during the postpartum period, but relatively little is known about factors contributing to this decreased anxiety. Using increased duration of time spent in the open arms of an elevated plus-maze as an indicator of reduced anxiety, it was found in a series of experiments that (1) anxiety is significantly reduced in Long-Evans females during the first week of lactation, but not thereafter, (2) relatively recent contact with pups before testing (within 4 h) is necessary for their reduced anxiety, (3) dams that receive only distal sensory cues from pups for the 4 h prior to testing do not show reduced anxiety, (4) the absence of nipples, and therefore a lack of suckling by pups, has no effect on dams' anxiety, (5) cesarean delivery of pups 2 days prior to expected parturition did not alter later anxiety in dams, (6) hypophysectomy during mid-pregnancy or ovariectomy within 24 h after parturition also did not prevent reduced anxiety in dams, and (7) differences in anxiety between lactating and virgin females are greatest 4-8 min after being placed in the plus-maze. Therefore, exposure to their own peripheral hormones through mid-pregnancy is sufficient to prime female rats to show reduced anxiety, but only if they later have recent physical interaction with pups. Furthermore, because suckling and the peripheral hormones released during suckling appear to be unnecessary, decreased anxiety in maternal rats may instead be regulated by the transient intracerebral release of neuropeptides or neurotransmitters while dams receive other types of tactile inputs from their infants.     

Hormonal correlates of changes in interest in unrelated infants across the peripartum period in female baboons (Papio hamadryas anubis sp.)

In past research on human and nonhuman primates, maternal responsiveness and behavior has been thought of as an experiential, cognitive mechanism; however, recent findings have shown that maternal motivation and behavior may not be entirely divorced from the endocrine system. To investigate the relationship between interest in infants and the hormonal changes related to pregnancy, we examined the nature of social interactions across parturition between a large sample (n = 133) of adult female baboons (Papio hamadryas anubis sp.) and unrelated infants. Prepartum data were collected during ten 30-min focal observations for each subject. Each mother-infant pair was then observed through the infant's first 8 weeks of life. A total of 2325 h of observation was recorded. Urine was collected on 65 subjects, starting 5 weeks before the expected date of parturition and ending 4 weeks after parturition. Evidence for a connection between endocrine function and responsiveness toward infants was found. Affiliative behaviors during the prepartum period were positively correlated to the estrogen/cortisol ratio and high dominance rank. In the postpartum period, affiliative behaviors were positively correlated with prepartum progesterone and dominance rank, and negatively correlated with postpartum cortisol levels. Finally, a positive correlation was recorded during the postpartum period between prepartum progesterone and aggression, and a negative correlation between postpartum cortisol and aggression and submission. Our data suggest that the endocrine changes that may help regulate maternal care of offspring also influence the way in which pre- and postpartum female baboons interact with unrelated infants in their social group.     

Role of maternal 5‐HT1A receptor in programming offspring emotional and physical development

Serotonin_1A receptor (5‐HT_1AR) deficiency has been associated with anxiety and depression and mice with genetic receptor inactivation exhibit heightened anxiety. We have reported that 5‐HT_1AR is not only a genetic but also a maternal ‘environmental’ factor in the development of anxiety in Swiss‐Webster mice. Here, we tested whether the emergence of maternal genotype‐dependent adult anxiety is preceded by early behavioral abnormalities or whether it is manifested following a normal emotional development. Pups born to null or heterozygote mothers had significantly reduced ultrasonic vocalization (USV) between postnatal day (P) 4 and 12, indicating an influence of the maternal genotype. The offspring's own genotype had an effect limited to P4. Furthermore, we observed reduced weight gain in the null offspring of null but not heterozygote mothers, indicating that a complete maternal receptor deficiency compromises physical development of the offspring. Except a short perinatal deficit during the dark period, heterozygote females displayed normal maternal behavior, which, with the early appearance of USV deficit, suggests a role for 5‐HT_1AR during pre‐/perinatal development. Consistent with this notion, adult anxiety in the offspring is determined during the pre‐/perinatal period. In contrast to heterozygote females, null mothers exhibited impaired pup retrieval and nest building that may explain the reduced weight gain of their offspring. Taken together, our data indicate an important role for the maternal 5‐HT_1AR in regulating emotional and physical development of their offspring. Because reduced receptor binding has been reported in depression, including postpartum depression, reduced 5‐HT_1AR function in mothers may influence the emotional development of their offspring.     

Increased depressive-like traits in an animal model of premenstrual irritability

Women are at higher risk of anxiety and mood disorders, especially at transitions across the reproductive life cycle (premenstruum, postpartum, menopause). Premenstrual dysphoric disorder (PMDD) is one of female mood disorders associated with changing ovarian hormone levels. Because anxiety and depression frequently occur in women with PMDD, premenstrual dysphoria might be a manifestation of certain vulnerability traits increasing the risk of those disorders. The present study was conducted to elucidate a potential association between estrous cycle-dependent aggression, the rodent model of "premenstrual irritability" (resident-intruder test), and anxiety (elevated plus maze), depressive-like traits (forced swim test) as well as carbohydrate craving in female Wistar rats. Some aggressive and nonaggressive females were restraint-stressed before testing to determine their sensitivity to stress at different hormonal stages. The results revealed that females expressing the estrous cycle-dependent aggression but not those not expressing cycle-dependent aggression spent longer time immobile and shorter time swimming in the forced swim test at metestrus compared to proestrus phase of the estrous cycle. There was no difference between aggressive and nonaggressive females in anxiety, locomotor activity and sensitivity to restraint stress and sucrose consumption. The present study suggests a common neurobiological background for the estrous cycle-dependent aggression and depressive-like traits in rodents. This phenomenon could potentially aid the elucidation of premenstrual emotional dysfunctions and might be used as an ethological model to study a biochemical and genetic proneness to depression.     

Effects of two estradiol regimens on anxiety and depressive behaviors and trophic effects in peripheral tissues in a rodent model

Background: With aging and menopause, which are associated with decreases in ovarian steroids such as 17β-estradiol (E₂), women might experience negative psychological symptoms, including anxiety and depression. Some women use E₂-based therapies to alleviate these symptoms, but E₂ has been associated with trophic effects that might increase vulnerability to some steroid-sensitive cancers, such as breast cancer, in both premenopausal and postmenopausal women.Objective: This study investigated the relationships between the possible beneficial effects of E₂ on anxiety and depressive behaviors concurrent with trophic effects using an animal model of E₂ decline and replacement.Methods: Dose-dependent effects of E₂ on affective, sexual, and motor behavior of young adult rats were studied. Ovariectomized (OVX) rats were administered the chemical carcinogen 7,12-dimethylbenz(a) anthracene (DMBA) 1.25 mg or inactive vehicle (vegetable oil; control) by gavage. E₂ (0.03 or 0.09 mg/kg) or vehicle was administered subcutaneously 44 to 48 hours before assessments of anxiety (light—dark transition), depression (forced swim test), sexual (lordosis), and motor (activity monitor) behaviors. Fourteen weeks after carcinogen exposure, E₂ concentrations in plasma and brain regions (cortex, hippocampus, and hypothalamus) were determined. Incidences and numbers of tumors and uterine weight were analyzed.Results: Administration of E₂ (0.09 mg/kg) was associated with significant increases in antianxiety-like behavior in the light—dark transition task, antidepressant-like behavior in the forced swim test, and physiologic circulating and central E₂ concentrations compared with E₂ (0.03 mg/kg) and vehicle. Compared with vehicle, E₂ (0.9 > 0.3 mg/kg) was associated with significant increases in lordosis and uterine weight. Administration of DMBA was associated with significant increases in the incidences and numbers of tumors; this effect was augmented by E₂administration.Conclusions: Based on the findings in this rat model, the hypothesis that E₂ may be effective in reducing anxiety and depressive behaviors and enhance sexual behavior in OVX rats, concurrent with trophic effects in the periphery, was supported. Moderate physiologic levels of E₂ might have beneficial effects on affective and sexual behaviors in female rodents, but regimens including E₂ might increase tumorigenic capacity.     

Diminished maternal responsiveness during pregnancy in multiparous female common marmosets

Common marmoset monkeys (Callithrix jacchus) live in small groups in which, usually, only a single female breeds and all group members provide infant care. When two females breed concurrently, however, they may commonly kill one another's infants, especially during the peripartum period. To investigate the mechanisms underlying infanticide by breeding females, we characterized responses of multiparous females to infants and determined circulating hormone levels in adult females during early pregnancy, late pregnancy, and the early postpartum period. Additionally, we compared the responses of postpartum females to their own infants and infants of other females (unfamiliar infants). Postpartum females were highly maternal toward both their own and unfamiliar infants, and showed no differences in their behavioral or hormonal responses to the two. During both early and late pregnancy, however, these females exhibited longer latencies to initially approach unfamiliar infants and spent less time carrying unfamiliar infants. Moreover, females spent less time carrying unfamiliar infants during late pregnancy than early pregnancy. Most late pregnant females never carried infants, and those that did rejected them quickly. Prolactin concentrations were higher and progesterone concentrations lower postpartum than in early or late pregnancy, while estradiol concentrations, the estradiol-to-progesterone ratio, and cortisol levels were higher during late pregnancy. Within reproductive conditions, however, maternal behaviors were not correlated with hormone levels. These results suggest that maternal responsiveness in marmosets may be attenuated during pregnancy, especially late pregnancy, and this may contribute to infanticide by breeding females.     

Prenatal ultrasound screening: false positive soft markers may alter maternal representations and mother-infant interaction

Background

In up to 5% of pregnancies, ultrasound screening detects a “soft marker” (SM) that places the foetus at risk for a severe abnormality. In most cases, prenatal diagnostic work-up rules out a severe defect. We aimed to study the effects of false positive SM on maternal emotional status, maternal representations of the infant, and mother-infant interaction.

Methodology and Principal Findings

Utilizing an extreme-case prospective case control design, we selected from a group of 244 women undergoing ultrasound, 19 pregnant women whose foetus had a positive SM screening and a reassuring diagnostic work up, and 19 controls without SM matched for age and education. In the third trimester of pregnancy, within one week after delivery, and 2 months postpartum, we assessed anxiety, depression, and maternal representations. Mother-infant interactions were videotaped during feeding within one week after delivery and again at 2 months postpartum and coded blindly using the Coding Interactive Behavior (CIB) scales. Anxiety and depression scores were significantly higher at all assessment points in the SM group. Maternal representations were also different between SM and control groups at all study time. Perturbations to early mother-infant interactions were observed in the SM group. These dyads showed greater dysregulation, lower maternal sensitivity, higher maternal intrusive behaviour and higher infant avoidance. Multivariate analysis showed that maternal representation and depression at third trimester predicted mother-infant interaction.

Conclusion

False positive ultrasound screenings for SM are not benign and negatively affect the developing maternal-infant attachment. Medical efforts should be directed to minimize as much as possible such false diagnoses, and to limit their psychological adverse consequences.     

Influence of Psychosocial Factors on Postpartum Weight Retention

For some women, pregnancy may increase the risk of future obesity with consequences for health and well‐being. Psychosocial factors may be partly responsible for this. The aim of this study was to examine the association between psychosocial factors during pregnancy and postpartum weight retention (PPWR) at 6 and 18 months. A total of 37,127 women in The Danish National Birth Cohort (DNBC; 1996–2002) participated in four telephone interviews before and after delivery. They gave information about their experience of distress, depression and anxiety, social support, and psychosocial burdens during pregnancy. PPWR was defined as retention ≥5 kg at 6 and 18 months postpartum according to a woman's prepregnancy weight. The associations were examined by use of logistic regression and presented as odds radios with 95% confidence intervals. Women who were more likely to feel depressed/anxious or distressed during pregnancy had a higher risk of PPWR at 6 months (1.35 (1.27; 1.44) and 1.30 (1.22; 1.38)) and 18 months (1.34 (1.24; 1.45) and 1.32 (1.23; 1.42)). Likewise, women who felt burdened by their economy or working situation had a higher risk of PPWR as did women with the lowest incomes or less education. Women who reported a high level of distress or depression/anxiety both during pregnancy and in the first 6 months of motherhood had the highest risk of PPWR 18 months postpartum (1.54 (1.39; 1.71) and 1.49 (1.32; 1.69), respectively). Feeling distressed, depressed, or anxious during pregnancy was associated with higher PPWR as was personal and economical burdens. Adverse psychosocial characteristics may be a common determinant of weight retention after childbirth.     

Sex differences in depression and anxiety disorders: potential biological determinants

The phenomenon of higher rates of affective disorders in women illustrates many of the difficulties as well as promises of translating preclinical models to human disorders. Abnormalities in the regulation of the hypothalamic-pituitary adrenal axis and the sympathoadrenomedullary system have been identified in depression and anxiety disorders, and these disorders are clearly precipitated and exacerbated by stress. Despite the striking sex difference in the prevalence of depression and anxiety disorders, attempts to identify corresponding sex differences in stress response reactivity in animal models have met with limited success. Processes which may contribute to increased rates of affective disorders in women are greater fluxes in reproductive hormones across the life span, and increased sensitivity to catecholamine augmentation of emotional memory consolidation.     

Separation Anxiety,Attachment and Inter-Personal Representations: Disentangling the Role of Oxytocin in the Perinatal Period

In this paper, we aimed to assess cross-sectionally and longitudinally associations between disturbances in maternal early attachment experiences, symptoms of separation anxiety and depression and oxytocin plasma levels. We examined a mediational model that tested the hypothesis that anxious attachment style arising from the mothers’ early bonding experiences with her own parents was associated with high levels of separation anxiety which, via its impact on depression, was associated with reduced levels of oxytocin in the postnatal period. Data is reported on a structured sample of 127 women recruited during pregnancy from a general hospital antenatal clinic and an initial follow up cohort of 57 women who were re-assessed at 3-months post-partum. We found an association between lower oxytocin level in the post partum period and symptoms of separation anxiety and depression during pregnancy, as well as maternal negative interpersonal representations, upbringing attributes and anxious attachment style. Further meditational analysis revealed that the unique association between anxious attachment and depression is mediated by separation anxiety and that depressed mood mediated the relationship between separation anxiety and oxytocin. In conjunction with evidence from the literature suggesting that lower oxytocin level is associated with bonding difficulties, our findings have significant implications for understanding the biological processes underpinning adverse attachment experiences, negative affect state, and mother-to-infant bonding difficulties.     

Parity-associated reductions in behavioral sensitivity to opiates

Behavioral and physiological responses differ between primiparous and multiparous female rodents. Specifically, multiparous females respond with the full repertoire of maternal behaviors much more rapidly and with greater intensity than their primiparous counterparts. Since opiates inhibit the expression of maternal behavior in postpartum rats and can be reversed by means of the opiate antagonist naloxone, we investigated whether multiparous females would be resistant to the inhibitory effects of opiates on maternal behavior, relative to primiparous females. In Experiment 1 we evaluated the effects of a range of doses of morphine sulfate (MS; 0.625, 1.25, 2.5, 5.0, and 10.0 mg/kg or saline) on maternal behavior in primiparous females on Days 5-6 of lactation. The 5.0 and 10.0 mg/kg doses effectively disrupted maternal behavior, whereas the lower doses were ineffective or only marginally disruptive. In Experiment 2, age-matched female rats were timed-mated and tested for maternal behavior from Day 5 to 13 of lactation, after daily injections of the 5.0 mg/kg dose of MS. On Day 5 of lactation, this morphine treatment eliminated full maternal behavior in 87% of the primiparous animals, but only 37% of the multiparous animals were affected. By Day 10 of lactation, 100% of the multiparous females displayed full maternal behavior after MS treatment, whereas only 69% of primiparous females were responsive. In Experiment 3, analgesic responses were measured both in rats experiencing their initial or second pregnancy, and in postpartum, lactating rats after MS (5.0 mg/kg) administration. Using a tail-flick apparatus to measure analgesia, we found multigravid females to be significantly less analgesic prepartum than primigravid females, suggesting less sensitivity to endogenous opioids.(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum NGF,BDNF and IL-6 Levels in Postpartum Mothers As Predictors of Infant Development: The Influence of Affective Disorders

Background

Early adverse experiences are associated with increased risk of developing psychiatric disorders, although little is known about the neurobiological mediators involved. The mechanisms by which early environmental influences may mediate vulnerability in the development of offspring await further investigation. The present study correlated the NGF, BDNF, IL-6 and cortisol levels of mothers with postpartum affective disorders (PPAD) with infant development.

Methods

A longitudinal study was performed with 152 pregnant women and their infants. Between 60 and 120 days after delivery, women were interviewed and provided biological samples for biochemical analysis, and the infants were examined for neurobiological-motor development.

Results

Overall, the mothers'' history of affective disorders, PPAD and anxiety disorder were associated with infant motor development. Using an adjusted linear regression analysis, PPAD (p = 0.049), maternal anxiety disorder (p = 0.043), NGF level (p = 0.034) and infant cortisol level (p = 0.013) were associated with infant motor development. Using a factorial analysis of primary components, two components were retained. The psychological factor was characterized by a positive loading of a history of affective disorder, PPAD and anxiety disorder. For the biological factor, infant cortisol adhered negatively with infant motor development, but NGF was positively associated. The psychological factor had a negative association, but the biological factor had a positive association with infant motor development.

Conclusions

There are few studies that have focused on the relationship of biomarkers and infant neurodevelopment. Our study points that psychological and biological factors are associated with infant motor development, however the causal relationship between these factors is still to be defined.