RECIPROCAL CONNECTIONS BETWEEN THE RABBIT SUPRAGENICULATE PRETECTAL NUCLEUS AND THE SUPERIOR COLLICULUS - TRACER STUDY WITH HORSERADISH-PEROXIDASE AND FLUOROGOLD

Connections of the rabbit suprageniculate pretectal nucleus (SP) with the superior colliculus were explored by means of retrograde transport of horseradish peroxidase or Fluorogold. Large injections centered in the superficial and intermediate tectal layers resulted in bilateral retrograde transport to the medium-size multipolar neurons of the supr ageniculate pretectal nucleus. Horseradish peroxidase was also transpo rted anterogradely into the ipsilateral and contralateral neuropiles o f the suprageniculate pretectal nucleus. The labeled cells in SP were dispersed throughout the nucleus, including its dorsal, wedge-shaped, internal portion. Labeling was mainly ipsilateral, and less abundant o n the contralateral side.