Neonatal maternal deprivation modifies feeding in response to pharmacological and behavioural factors in adult rats

Association between maternal psychological adversity and lung function in South African infants: A birth cohort study

OBJECTIVE

The association of perinatal psychological adversity (ie, stressors and distress) with infant lung function (ILF) and development is not well studied in Africa and elsewhere. We determined the association between maternal perinatal psychological adversity and ILF in African infants.

DESIGN

Prospective longitudinal follow up of the Drakenstein Child Health Study birth cohort.

PARTICIPANTS

Seven hundred and sixty-two infants aged 6 to 10 weeks and 485 infants who had data for both maternal perinatal psychological adversity and ILF (measured at 6 to 10 weeks and 12 months).

METHODS

The main analyses were based on cross-sectional measures of ILF at each assessment (6 to 10 weeks or 12 months), using generalized linear models, and then on the panel-data of both longitudinal ILF assessments, using generalised estimating equations, that allowed specification of the within-group correlation structure.

RESULTS

Prenatal intimate partner violence (IPV) exposure was associated with reduced respiratory resistance at 6 to 10 weeks (beta coefficient [β] = -.131, P = .023); postnatal IPV with reduced ratio of time to peak tidal expiratory flow over total expiratory time (tPTEF /tE ) at 12 months (β = -.206, P = .016); and prenatal depression with lower respiratory rate at 6 to 10 weeks (β = -.044, P = .032) and at 12 months (β = -.053, P = .021). Longitudinal analysis found an association of prenatal IPV with reduced tPTEF /tE (β = -.052, P < .0001); postnatal IPV with decreased functional residual capacity (FRC; β = -.086, P < .0001); prenatal posttraumatic stress disorder with increased FRC (β = .017, P < .0001); prenatal depression with increased FRC (β = .026, P < .0001) and postnatal depression with increased FRC (β = .021, P < .0001).

CONCLUSION

Screening for psychological adversity and understanding the mechanisms involved may help identify children at risk of altered lung development and inform approaches to treatment.

Early postnatal maternal separation causes alterations in the expression of β3-adrenergic receptor in rat adipose tissue suggesting long-term influence on obesity

The effects of early postnatal maternal deprivation on the biological characteristics of the adipose tissue later in life were investigated in the present study. Sprague-Dawley rats were classified as either maternal deprivation (MD) or mother-reared control (MRC) groups. MD was achieved by separating the rat pups from their mothers for 3h each day during the 10-15 postnatal days. mRNA levels of mitochondrial uncoupling protein 1 (UCP-1), β3-adrenergic receptor (β3-AR), and prohibitin (PHB) in the brown and white adipose tissue were determined using real-time RT-PCR analysis. UCP-1, which is mediated through β3-AR, is closely involved in the energy metabolism and expenditure. PHB is highly expressed in the proliferating tissues/cells. At 10 weeks of age, the body weight of the MRC and MD rats was similar. However, the levels of the key molecules in the adipose tissue were substantially altered. There was a significant increase in the expression of PHB mRNA in the white adipose tissue, while the β3-AR mRNA expression decreased significantly, and the UCP-1 mRNA expression remained unchanged in the brown adipose tissue. Given that these molecules influence the mitochondrial metabolism, our study indicates that early postnatal maternal deprivation can influence the fate of adipose tissue proliferation, presumably leading to obesity later in life.

Comparative analysis of physiological adaptation of neonates of abused and nonabused mothers

The investigators examined: (a) the relationships between the mother's abuse status and the newborn's stress responses, and (b) differences in newborn stress responses of abused and nonabused mothers before and after a phenylketonuria (PKU) heel stick. The t-tests show a trend toward statistical significance. Abuse had strong effect sizes on cortisol and oxygen levels at 25 minutes. Findings support further research on the impact that maternal stress resulting from abuse has on neonatal outcomes.

Antenatal glucocorticoids blunt the functioning of the hypothalamic-pituitary-adrenal axis of neonates and disturb some behaviors in juveniles

Antenatal glucocorticoids are highly effective in preventing respiratory distress of premature babies but can induce physiological and behavioral disturbances in young infants as well as in animals. Therefore, the hypothalamic-pituitary-adrenal (HPA) axis of rat neonates, and the consequences on behavioral development of offspring have been studied after five antenatal injections of dexamethasone (DEX) or vehicle. DEX decreased offspring body weight at birth, and significantly delayed the normal growth for the first 3 weeks of life. This paralleled diminished behavioral performances measured on postnatal day 3 (righting reflex) and postnatal day 10 (grasping test). Circulating levels of adrenocorticotrophin (ACTH) and corticosterone were significantly decreased on postnatal day 1 and this was related to a diminution of HPA axis activity shown by the decrease of central expression of corticotropin releasing hormone (CRH) mRNA, immunoreactive content in paraventricular neurons (PVN) and in the median eminence endings were significantly decreased. On the other hand, expression of another secretagogue of ACTH, arginine vasopressin (AVP), was differently affected in the PVN parvocellular neurons of offspring of the DEX group since AVP mRNA increased whereas immunoreactive content of the PVN parvocellular neurons was lowered. Simultaneously, the co-production of AVP and CRH in PVN neurons was stimulated. This can support the view that antenatal DEX reached the fetus and produced some damage which did not parallel that induced by prenatal stress of the pregnant females, especially the low body weight of offspring. The harmful consequence of antenatal DEX treatment was not restrictively due to the blunting of the HPA axis but also to the low body weight, which disturbed behavioral performances for the first weeks of life and could participate in other disorders in adult life.

Early maternal deprivation induces alterations in brain-derived neurotrophic factor expression in the developing rat hippocampus

The effects of maternal deprivation (MD) during early postnatal life on the brain-derived neurotrophic factor (BDNF) level were investigated in the present study. Wistar rats were assigned to either maternal deprivation or mother-reared control (MRC) groups. MD manipulation was achieved by separating rat pups from their mothers for 3h a day during postnatal days (PND) 10-15. At 16, 20, 30, and 60 days of age, the level of BDNF mRNA in the hippocampal formation of each group was determined using real-time PCR analysis. Early postnatal maternal deprivation of rat pups resulted in a significant increase in body weight at 60 days of age. The expression of BDNF mRNA in the hippocampus was significantly decreased at 16 days of age, and increased at 30 and 60 days of age. These data indicate that even a brief period of maternal deprivation during early postnatal life can affect hippocampal BDNF expression.