Brain neurotransmitters in an animal model with postpartum depressive-like behavior.

Post-Partum Depression (PPD) occurs in 15% of pregnancies and its patho-physiology is not known. We studied female BALB/c ("depressive") and C57BL/6 (control) mice as a model for PPD and assessed their behavior and correlates with brain neurotransmitters (NTs) - norepinephrine, dopamine, serotonin and intermediates, during the pre-pregnancy (PREP), pregnancy (PREG) and post-partum (PP) periods. Depressive-like behavior was evaluated by the Open Field (OFT), Tail Suspension (TST) and Forced Swim (FST) tests. Neurotransmitters (NTs) were determined in the striatum (care-giving), hippocampus (cognitive function) and hypothalamus (maternal care & eating behavior). In the BALB/c mice, while their performance in all behavioral tests was significantly reduced during pregnancy and P-P indicative of the development of depressive-like responses, no changes were observed in the C57BL/6 mice. Changes in NTs in BALB/C were as follows: PREP, all NTs in the three brain areas were decreased, although an increase in dopamine release was observed in the hippocampus. PREG: No changes were observed in the NTs except for a decrease in 5-HT in the striatum. P-P: striatum, low 5-HT, NE and dopamine; Hippocampus: low 5-HT, NE and high Dopamine; hypothalamus: all NTs increased, especially NE. Following pregnancy and delivery, the BALB/c mice developed depressive-like behavior associated with a significant decrease in 5-HT, dopamine and NE in the striatum and 5-HT and NE in the hippocampus. Dopamine increased in the latter together with a significant increase in all NTs in the hypothalamus. These findings suggest that the development of PPD may be associated with NT changes. Normalization of these alterations may have a role in the treatment of PPD.

The oxytocin-CD38-vitamin A axis in pregnant women involves both hypothalamic and placental regulation.

OBJECTIVE: Oxytocin, a hypothalamic hormone secreted upon release of ectoenzyme CD38, plays a vital role in interpersonal bonding behaviors. Reduced plasma oxytocin characterizes autistic individuals. CD38 levels, which were found to be low in LBCs derived from autistic patients, is upregulated upon the addition of a vitamin A derivative. During pregnancy, oxytocin is also secreted by placenta. Recent controversial studies have suggested an increased risk for autism when oxytocin is used during induction and augmentation of labor. We aimed to examine the tripartite relationship between oxytocin, CD38 and vitamin A in pregnant women and their newborns. METHODS: Thirty-one healthy expectant mothers were enlisted for this study. Levels of oxytocin, CD38 and ATRA were measured in both maternal peripheral and newborn cord blood, and the tripartite relationship between these parameters examined. Estrogen and progesterone levels of the mothers were also recorded. Several clinical measures were also noted. RESULTS: Mean maternal oxytocin and vitamin A levels were approximately 8- and 4-fold higher, respectively, than neonatal levels. CD38 expression, however, was 9 times higher in neonates than in the maternal group. Positive correlation was found between maternal and cord blood for both oxytocin and CD38. CONCLUSIONS: This establishment of normative values for oxytocin, CD38 and vitamin A in healthy pregnant women and newborns may serve as a reference in the investigation of developing pathologies of disorders such as autism.