Efferent connections of cortical, area 8 (frontal eye field) in Macaca fascicularis. A reinvestigation using the autoradiographic technique.

The efferent projections from the cortical area 8 (frontal eye field) have been re-examined in four adult monkeys (Macaca fascicularis) by injecting small amounts of H3-proline into the rostral bank of sulcus arcuatus and using the autoradiographic tracing technique. Ipsilateral cortical projections could be traced into specific areas of the depths of sulcus principalis, sulcus temporalis superior and sulcus intraparietalis. Label was found contralaterally in area 8. Subcortical connections were observed ipsilaterally to n. caudatus, putamen, claustrum, n. ventralis anterior pars magnocellularis, n. medialis dorsalis pars multiformis and pars densocellularis, n. centralis lateralis and paracentralis, n. parafascicularis, n. pulvinar oralis, zone incerta, n. subthalamicus, pretectal area, colliculus superior and griseum pontis as well as the ipsi- and contralateral n. reticularis tegmenti pontis. Negative results were obtained with respect to the oculomotor nuclei, n. interstitials and Darkschewitsch as well as to the paramedian pontine reticular formation.