Abscisic acid regulates maternal behavior in rats via PPARγ receptors and hypothalamic oxytocin signaling

Abscisic acid (ABA) is present in brain regions associated with parental care and aggression. Maternal care is pivotal in early mammalian development, significantly influencing emotional regulation, stress resilience, and adaptive fitness in offspring.

The present study investigates the influence of intra-paraventricular nucleus (PVN) administration of ABA on maternal behavioral responsiveness in lactating female rats.

On postpartum day 5, lactating rats (n=6 per group) received intra-PVN injections of ABA (5, 10, or 20 µg/rat) via stereotaxic surgery. Ten min after injection, maternal behaviors, including durations of low and high kyphosis, pup retrieval times, and durations of body and anogenital licking were recorded for 1 h. Additionally, the percentage of oxytocin-immunoreactive cells in brain was quantified.

ABA administration (20 μg/rat) significantly enhanced most maternal behavior indices (P<0.05). These ABA-induced improvements in maternal care were significantly inhibited by GW9662, a peroxisome proliferator-activated receptor γ (PPARγ) antagonist (P<0.01). Furthermore, ABA treatment significantly increased number of oxytocin-immunoreactive cells in the paraventricular (Pe) and anterior parvocellular parts (PaAP) of the PVN (P<0.001); this increase was reversed to control levels following blockade of PPARγ receptors (P<0.001).

These findings suggest that central ABA administration can enhance maternal care behaviors in lactating rats, potentially through activation of PPARγ signaling and increased expression of oxytocin in the maternal brain. However, further research is required to determine whether ABA has a physiological role under normal conditions.