The aim of this work was to investigate the distribution of neurotransmitter positive elements in the ovaries of two-month-old female rats in estrus using histochemistry and immunohistochemistry. Acetylcholinesterase (AChE)-positive fibers were demonstrated in the interfollicular tissue, theca externa, mesovarium and hilum, while intracellular deposits were found in granulosa cells. Dopamine (DA)-positive reaction was demonstrated in cortical nerve bundles, in fine fiber networks between and around follicles or secondary interstitial cells. Delicate 5-hydroxytriptamine (5-HT)-positive fibers were present under the surface epithelium, and 5-HT-positive cells in the hilum, medulla and in the mesovarium. Gamma-aminobutyric acid (GABA) immunostaining was present in the cytoplasm of granulosa cells and in the hilum and mesovarium. Our results confirm that neurotransmitter supply of the ovary is not only via extrinsic innervation and that intragonadal sources have a role in their synthesis
