Retinohypothalamic pathway in the dove demonstrated by anterograde HRP

The hypothalamic suprachiasmatic nucleus (SCN) of the ring dove was demonstrated by the presence of labeled retinal processes. Horseradish peroxidase or tritiated proline were injected into the vitreous of the eye and were transported in an anterograde manner to label the SCN. After identifying the retinorecipient area of the hypothalamus by anterograde tracing procedures, a diffusely organized nucleus corresponding to this region was noted in Nissl material.