MATERIAL and METHODS: One hundred fertile specific pathogen-free (SPF) chick eggs were used to investigate neurulation; they were divided into four groups of 25 eggs (Groups A, B, C, and D including control, subtherapeutic, therapeutic, and supratherapeutic dose subjects, respectively). After 30 hours of incubation, all eggs reached the ninth stage of embryonic development, as defined by Hamburger and Hamilton. GBP was administered through the subblastoderm, and the eggs were incubated for 72 hours. The embryos were macroscopically and histopathologically investigated with hematoxylin eosin following incubation and extraction.

RESULTS: In the 72nd hour of the study, a total of 6 eggs showed no embryo development. We detected 1 (4.34%), 13 (59.09%), 15 (65.21%), and 18 (81.81%) neural tube defective embryos in groups A, B, C, and D, respectively. Statistically, the differences between the groups were significant, especially in the comparisons of all GBP groups to the control group (p?0.001). However, there was no significant difference between groups B, C, and D. Additionally, we suggest that at all doses, GBP could cause neural tube defects in the ESCE.

CONCLUSION: Based on these results, we concluded that GBP use at any dose led to midline closure defects in ESCEs. This is the first report in the literature on GBP using an ESCE model. However, further investigations with a larger sample size are required to assess its effect at lower doses and to determine the mechanisms of embryonic damage. Keywords : Neural tube defect, Early chick embryo, Neurulation, Gabapentin