[Differentiation of efferent projections of the medial (cuneiform nucleus) and lateral areas of the reticular formation of the midbrain in the cat].

Efferent connections of medial (nucleus cuneiformis) and lateral regions of the caudal part of the midbrain reticular formation (mRF) were investigated by anterograde autoradiographic method in cat. Projections from the mRF ascend to the globus pallidus, substantia innominata, hypothalamus, subthalamus and nonspecific, associative and relay nuclei of the thalamus. Descending pathways terminate in the reticular formation of the brain stem. The conclusion is made that the cuneiform nucleus is rather a nonspecific than auditory centre. The lateral reticular region has strong projections to the lateral geniculate body and together with the parabigeminal nucleus forms the midbrain visual complex.