In chronic experiments on cats, microelectrode studies of the caudate nucleus' head revealed topic and functional directions of nigral influences by means of reversible suppression of different portions of its compact and reticular areas. The most obvious inhibitory influences come to the caudate nucleus' head ventromedial segment from the medial portion of the black substance. The latter's lateral and central portions expedite impulsation toward the dorso--lateral and respective medial segments with activating influences prevailing. The revealed topic distribution of functionally different nigral afferents corroborates the morphofunctional heterogeneity of the nigro--caudal relation, the latter reflecting the complexness and diversity of this subsystem's participation in the brain integrative activity.