Histomorphological changes in lumbar sympathetic chain ganglia of the female pig during prenatal development

This study presents, for the first time, a histomorphological analysis of the lumbar sympathetic chain ganglia (L SChG) during prenatal development in 5-, 7-, and 10-week-old female porcine foetuses. Single immunohistochemical staining for protein gene product 9.5 (PGP) as a neural marker has shown that in 5-week-old foetuses, the ganglia appeared as paired, structures adjacent to the dorsolateral aspect of the descending aorta, measuring approximately 170-190 μm in diameter, composed of small oval neurons (6-8 μm) with large nuclei and scant cytoplasm. They formed elongated, oval structures, like a segmented column, with slight variations in shape and size. By seven weeks, the ganglia had grown to 270-200 μm, becoming broader than tall, while the neurons enlarged to 8-11 μm and took on a more rounded shape. At 10 weeks, L SChG showed significant growth and morphological diversity (up to 530-630 μm), with neurons varying in shape (oval, round, triangular) and size (12-16 μm). The progressive enlargement and neuronal differentiation of L SChG suggest functional maturation relevant to autonomic innervation of the abdominal and pelvic viscera. The findings may aid early diagnosis of neurodevelopmental disorders, optimize prenatal care, and support broader veterinary insights into autonomic development across mammals.