Sympathetic sprouting in dorsal root ganglia (DRG): a recent histological finding?

During the nineties it was described, as an original finding, the existence of afferent amyelinic nerve endings in animal dorsal root ganglia (DRG) caused by diverse experimental lesions. These works do not take into account the historical studies carried out by Ehrlich (1886), Ramón y Cajal (1890) and Dogiel (1885) among others. Ramón y Cajal (1899) confirmed the existence of these nerve endings naming them after their discoverer as "Dogiel's arborisations".

Histomorphometrical study of the submandibular gland ductal system in the rat.

The duct system of murine submandibular gland is composed, in contrast with other mammals, by four types of ducts, among which the granular duct is unique for rodents. The granular duct shows a typical secretory structure with a clear intersex morphological diversity on which we carried out a morphometrical study in order to determine the relative area of each duct in rats in comparison with the rest of ducts and the whole gland. Our results, in both sexes, show that the duct with the broadest surface is the granular duct, followed by the excretory, striated and the intercalated ducts.