Innervation of the female internal genital organs in 12-week-old porcine foetuses

This is the first study aimed to investigate the innervation of the internal genital organs in 12-week-old female pig foetuses using single and double-labelling immunofluorescence methods. Immunostaining for protein gene product 9.5 (PGP, general neural marker) revealed that the most numerous PGP-positive nerve fibres were found in the mesenchyme of the uterovaginal canal height. Numerous nerve fibres were distributed in the uterine segment, less in the tubal segment of paramesonephric ducts (PD), and they usually occurred at the edge of the mesenchyme. A low number of fibres was visible in the developing ovary cortex and medulla. Many fibres expressed dopamine β-hydroxylase (DβH) and/or vesicular acetylcholine transporter (VAChT) in the studied period. Most DβH-positive nerve fibres were observed in all segments of PD. VAChT-positive were mainly distributed in the uterovaginal canal of PD. DβH/VAChT-positive nerve fibres were observed in the mesenchyme of all segments of the PD, but they were most common in the uterovaginal canal and the uterine segment of PD. In the ovary, nerves were mainly DβH-positive and single nerve fibres containing VAChT. Few DβH/VAChT-positive nerve fibres were observed in the ovary.