THE TERMINATION OF SPINOTHALAMIC FIBRES IN THE CAT AS STUDIED BY THE METHOD OF TERMINAL DEGENERATION

Abstract

Following transection of the spinothalamic fibers at different levels of the spinal cord or lesions of dorsal horn in the cat, the ensuing degeneration of terminal fibers and boutons within the thalamus has been studied by means of the Glees modification of the Bielschowsky method. The main bulk of the fibers terminates within the nucleus ventralis posteroiateralis, and the terminal fibers are somatotopically localized as descr. by previous authors. Terminal degeneration is also found within the posterior parts of the lateral and the reticular nuclei and in the nucleus centralis lateralis and the nucleus paracentralis. Also with unilateral lesions of the spinothalamic tracts terminal degeneration appears bilaterally, but is more marked homo-laterally. There is some indication that the fibers to the intralaminar nuclei pass through the ventral spinothalamic tract.