Fiber connections of the forel H-field as seen in marchi preparations

An anatomical study was made to follow the degeneration of fibers by means of Marchi technique in cat after making experimentally lesion in Forel H field. As the results the following conclusions were reached. 1) The ipsilateral distribution of the degenerated granules was in the anterior sigmoid gyrus, caudate nucleus, putamen and globus pallidus, thalamic nuclei medial to the internal medullary lamina, substantia nigra, rubrocerebellar system, medial longitudinal fascicle system, mesencephalic and pontine reticular formation and medial lemniscus. 2) There was also contralateral distribution to the interpositus and dentatus nuclei of the cerebellum via brachium conjunctivum, to globus pallidus via supraoptic commissure, to subthalamic region and substantia nigra via supramammilary commissure, and to red nucleus via tegmental decussaion. 3) The degeneration is so extensive that the Forel H-field seems to be the cross road of the extrapyramidal system in association with brainstem activating system.