| Neonatal neural injury has been well studied in terms of recovery and plasticity, yet the potential
moderating role of maternal care remains underexplored. This study examined how rat dams
respond to pups with a spinal cord transection and whether maternal olfactory disruption
(hyposmia) alters these responses. Forty female Sprague Dawley rats were assigned to either
intranasal zinc sulfate (ZnSO₄; hyposmia) or distilled water (control), and their litters received
either a complete spinal cord transection or sham surgery on postnatal day 1. Maternal
behaviors—including licking/grooming, anogenital licking, nursing, retrieval, and nest
building—were observed for 12 hours undisturbed and in the home cage on postnatal days 4, 8,
and 12. Results showed that control dams provided significantly less licking/grooming,
anogenital licking, and nursing to transected litters compared to sham litters, suggesting that
dams discriminate pup injury cues. In contrast, ZnSO₄-treated dams exhibited reduced overall
anogenital licking but did not differentiate between injured and sham pups, indicating that
olfaction mediates maternal discrimination. Maternal behaviors declined with pup age, consistent
with typical developmental trajectories, but differences between groups were most pronounced
early in development. These findings highlight maternal care as a key factor that may compound
or buffer developmental outcomes following neural insult and underscore the role of olfactory
cues in shaping dam–pup interactions.
Keywords: Infant-Caregiver Interaction, Neonatal Injury, Olfaction, Parental Behavior, Sensory
Cues |