Effects of pre-gestational exposure to the stressors and perinatal bupropion administration on the firing activity of serotonergic neurons and anxiety-like behavior in rats

Exposure by women to stressors before pregnancy increases their risk of contracting prenatal depression, a condition which typically may require antidepressant treatment. And even though such perinatal antidepressant treatment is generally considered to be safe. For the mother, its effects on the development and functioning of the offspring`s brain remain unknown. In this study, we aimed to investigate the effects of pregestational chronic unpredictable stress (CUS) and perinatal bupropion on the anxiety behavior and firing activity of the dorsal raphe nucleus (DRN) serotonin (5-HT) neurons. Female rats underwent CUS for three weeks before mating. Bupropion was administered to them from gestation day ten until their offspring were weaned. Behavioral (elevated plus maze or EPM test) and neurophysiological (single-unit in vivo electrophysiology) assessments were performed on offspring who reached the age of 48-56 days. We found that maternal CUS and perinatal bupropion, as separate factors on their own, did not change offspring behavior. There was, however, an interaction between their effects on the number of entries to the open arms and time spent in the intersection: maternal CUS tended to decrease these values, and perinatal bupropion tended to diminish CUS effect. Maternal CUS increased the firing activity of 5-HT neurons in males, but not females. Perinatal bupropion did not alter the firing activity of 5-HT neurons but tended to potentiate the maternal CUS-induced increase in 5-HT neuronal firing activity. The CUS-induced increase in firing activity of 5-HT neurons might be a compensatory mechanism that diminishes the negative effects of maternal stress. Perinatal bupropion does not alter the offspring`s anxiety and firing activity of 5-HT, but it does intervene in the effects of maternal stress.

Assessing the Independent and Joint Effects of Unmedicated Prenatal Depressive Symptoms and Alcohol Consumption in Pregnancy and Infant Neurodevelopmental Outcomes

BACKGROUND

Prenatal alcohol exposure (PAE) is an established risk factor for neurodevelopmental deficits in the offspring. Prenatal depression has been associated with neurodevelopmental deficits in the offspring, although investigations into unmedicated prenatal depression have been inconsistent. We hypothesized that unmedicated prenatal depressive symptoms would independently and jointly with PAE predict neurodevelopmental outcomes in infant offspring.

METHODS

We studied 344 participants from a randomized clinical trial of multivitamin supplements in pregnant women in Ukraine. Women were recruited based upon periconceptional alcohol use and followed up to 12 months postpartum. Prenatal depressive symptoms were assessed at approximately 32 weeks of gestation using the Beck Depression Inventory score. Neurodevelopment was assessed with the Bayley Scales of Infant Development II Mental Development Index (MDI) and Psychomotor Development Index (PDI) at 6 and 12 months postpartum. Generalized linear regression models were constructed to assess the independent and joint effects of prenatal depressive symptoms and PAE in models adjusted for sociodemographic and pregnancy characteristics.

RESULTS

PAE was independently associated with deficits in neurodevelopmental outcomes at 6 and 12 months, however, level of prenatal depressive symptoms was not. We found marginal evidence of synergism of depressive symptoms and PAE, with larger deficits in those with both exposures observed for the PDI-6 months (p = 0.05) and MDI-12 months (p = 0.09). Additionally, there was a suggestion of sexual dimorphism; females had stronger deficits from joint exposures than males (depressive symptom [MDI-6 months] female: -8.28, 95% CI -13.06, -3.49; male: 0.68, 95% CI -4.58, 5.94; p for interaction 0.04). While not statistically significant for the MDI or PDI at 12 months, the trend persisted.

CONCLUSIONS

Infants exposed to PAE and prenatal depression may be at an increased risk of neurodevelopmental deficits. Healthcare providers should be aware of this possible synergism in their efforts to mitigate the neurodevelopmental effects of these co-occurring exposures.