Fine structure of the paraventricular magnocellular neurons in the domestic fowl.

The morphology of the PVN of the domestic fowl (Gallus domesticus) was studied by the Golgi method and the electron microscope. The magnocellular neurons of the PVN are periventricularly scattered, in the region caudal to the anterior commissure, and they are situated in small clusters. Their ultrastructural features are the presence of a large amount of cytoplasm containing also few dense-core vesicles (1100--1500 A in diameter). In the neuropil axosomatic and axodendritic synapses are seen. Some of these show also dense-core vesicles (600--900 A).