Location of efferent and afferent neurons innervating the ovary in the hen.

Efferent and afferent neurons were labeled by injections of horseradish peroxidase into the ovary of the hen. Sympathetic postganglionic neurons were located in the paravertebral ganglia T2-LS2 (28% of total number of labeled neurons) and prevertebral ganglia (36%). Parasympathetic preganglionic neurons were located in the dorsal motor nucleus of the vagus (7%). Sensory neurons were found in the dorsal root ganglia T2-LS2 (28%) and nodose ganglia (under 1%). Although in the hen only the left ovary is functional, the labeled neurons were found bilaterally except for nodose ganglia. The significance of bilateral innervation in the ovary of the hen needs further investigations.