[Effect of thyroxine and methylthiouracil on the development of intramural ganglia in the chick embryo digestive tube].

The development of the vegetative muscular-gastric plexus ganglia has been studied in 17-day-old chick embryos at administration of thyroxin and the inhibitor of its production - methylthiouracil. The substances in question are injected into the air chamber of the egg on the 3d days of incubation. In histological preparations, stained after Nissl, with hematoxylin - eosin and silver impregnated, the total number of cells of the neuroblastic line and that of differentiated neurons are calculated in 50 ganglia. Under thyroxin effect the number of the differentiated neurons in the ganglia increases, while the total number of the neuroblastic cells (comparing to the control) remains constant. Under methylthiouracil effect the number of the differentiated neurons decreases and so does the total number of the neuroblastic cells. Thyroxin and methylthiouracil differently affect the differentiation rate of the neurons at various stages of this process. The effect of the drugs applied is poorly manifested in the duodenum, where (in the control) the total portion of the differentiated cells is higher than in other segments of the digestive tube, and the number of the ganglia without such cells is lower, while the portion of the ganglia with numerous differentiated neurons is more significant.