Sources of the porcine testis innervation

Summary This study was carried out on three adult male pigs of the large White Polish breed weighing 110–130 kg each. The animals were anaesthetised and injected with retrograde tracer Fast Blue (FB) into right testis. Three weeks later, the pigs were deeply anaesthetised and perfused transcardially with fixative (4% paraformaldehyde in 0.1  m phosphate buffer pH 7.4). Collected ganglia were cut with freezing microtome into 12‐ μm‐thick sections. The sections were examined under a fluorescent microscope (Zeiss). FB‐positive neurones were found in pelvic ganglia (anterior pelvic ganglion) (15.4% of all FB + neurones), prevertebral ganglia (caudal mesenteric, testicular, aortico‐renal and renal ganglia) (59% of all FB + neurones), sympathetic chain ganglia (last four lumbar and first three sacral ganglia) (18.1% of all FB + neurones) and dorsal root ganglia (DRG) (first three lumbar and first three sacral ganglia) (7.4% of all FB + neurones). The majority of FB‐positive nerve cell bodies were observed in ipsilateral ganglia, but they were also found in contralateral ganglia (approximately 85% and 15% respectively). Thus, FB‐positive neurones were located in the left prevertebral, sympathetic chain and DRG, but surprisingly, they were absent in left anterior pelvic ganglia.