Abstract

Background:
Pediatric dysphagia is a prominent feature of neurodevelopmental disorders, such as Prader–Willi syndrome (PWS). Dysphagia increases the risk of malnutrition, aspiration, and subsequent respiratory infections, highlighting the importance of improving the understanding and management of dysphagia.

Aim:
The present study investigated the potential role of oxytocin (OXT) in advancing feeding and swallowing behaviors in postnatal day 0 (P0) to P42 (6-week-old) rats, with potential therapeutic implications for PWS. We hypothesized that OXT administered subcutaneously in Sprague Dawley rats within 12 to 24 hours of birth would accelerate the maturation of feeding and swallowing behaviors compared to naïve and saline-treated controls.

Methods: Importantly, the videofluoroscopic swallow study (VFSS) protocol was successfully adapted to evaluate rats as young as P21, broadening the application of this protocol beyond the previous limitation of 6-week-old rats. Using an adapted VFSS protocol for juvenile (P21–P35) and peripubertal (P36–P42) rats, feeding and swallowing maturation was objectively characterized using custom JawTrack™ software. Protocol adaptations included the refinement of oral contrast formulations for liquid and solid foods and the optimization of fluoroscope settings and equipment. Body weight and developmental milestones (e.g., crawling, walking, self-feeding) were also recorded.

Results:
OXT modulated specific feeding behaviors in juvenile rats (i.e., lick rate and inter-lick interval). However, OXT did not significantly accelerate the attainment of developmental milestones in rats, and the selective effects on feeding behaviors were not observed to extend into the peripubertal stage.

Conclusion:
The present study establishes a useful methodology for future research using our enhanced VFSS protocol. In light of these results, future research is well-positioned to expand our understanding of the potential of OXT to treat dysphagia in neurodevelopmental disorders.

Key words: Behavior development, Neurodevelopment, Rats, Swallowing physiology