Vasotocin-immunoreactive elements and neuronal typology in the suprachiasmatic nucleus of the chicken and Japanese quail.

A Golgi study of the suprachiasmatic nucleus (SCN) of the chicken and Japanese quail revealed in this area a complex neuronal pattern and typology, including specialized dendritic patterns. Immunocytochemical studies provided evidence for the existence of a vasotocinergic system within the SCN, mainly in its rostral portion. Other clusters of immunoreactive elements are located in the lateral and dorsal divisions of this nucleus; they show a different distribution in the chicken and Japanese quail. The present results confirm, in birds, the existence of a morphologically defined SCN, the complex cytoarchitecture of which suggests specialized functions.