SOME SUBCORTICAL EFFERENT CONNECTIONS OF THE LATERAL THALAMIC NUCLEUS

Abstract

This modified Nauta and Ryan technique has the added advantages of not requiring special fixatives, is rapidly performed and is adapted equally well to paraffin and celloidin sections with one procedure. It selectively impregnates axons of both normal and degenerating tissue, independent of their myelinization; with the other procedure, it selectively impregnates degenerating axons. This technique has been applied to tracing efferent fibers in the region of the lateral thalamic nucleus, demonstrating the efficacy of this technique and serving as a prototype for other studies in various regions of the brain. With the reported techniques which have been applied to the tracing of the efferent fibers from the lateral thalamic nucleus of the cat, the course, distribution and termination of these fibers have been ascertained. On the ipsilateral side fibers were distributed to the pulvinar, lateral geniculate body, dorso-medial thalamic nucleus, center median, midline nuclei, caudate nucleus, zona incerta and the dorsal hypothalamic nucleus. On the contralateral side fibers were distributed to the nuclei ventralis anterior, lateralis dorsalis and the lateralis posterior, dorso-medial nucleus and the center median nucleus.