A single-unit analysis of the organization of Deiters' nucleus.

Abstract

Deiters'' cells projecting to the lumbosacral and cervicothoracic cord (L and C cells) were studied extracellularly in decerebellated cats anesthetised with chloralose-urethan. L cells predominate in the dorsocaudal region of the nucleus and C cells somewhat outnumber L cells in the rostroventral area, but there is great overlap between the two types of cells. Many C and L cells fire spontaneously, and most of these spontaneously active cells are in the dorsal half of the nucleus. Most spontaneous C and L cells can be facilitated, in a very generalized way, by stimulation of fore- and hind-limb nerves. Stimulation of the ipsilateral labyrinth fires 51% of C cells and 22% of L cells monosynaptlcallyi Many more non-spontaneous than spontaneous cells are fired, because most cells fired by the labyrinth are in the ventral half of the nucleus. The results show that Deiters''s cells projecting to all levels of the cord are under the influence of the labyrinth and the periphery, and provide physiological evidence for the subdivision of Dieters'' nucleus, particularly into dorsal and ventral regions.