Abstract
Contrary to the widespread belief ( 1-6 ) that taste organs are dependent upon the trophic action of the gustatory nerve for development and maintenance, it has been demonstrated that amphibian taste organs can develop independently ( 7 , 8 ) and denervated organs can be maintained for at least 6 months ( 9 ). The present experiments not only support this, but extend the investigations to show that denervated taste organs can exist for at least 12 1/2 months.
To effect permanent removal of gustatory nerve influence, autoplastic grafts of tongue tip to orbit (eye and eyelids removed) were made in adult Triturus v. viridescens under light chloretone anesthesia. Before recovery from the anesthetic, the animals were wrapped in wet absorbent cotton and kept in moist chambers in the icebox for 48 hours to prevent accidental removal of the graft. They were then placed in aquaria where the graft would be bathed by water at all times. In 90% of the cases circulation was re-established within one week and the grafts “took.” In the process of establishment, varying amounts of resorption occurred. Also during the progress of the experiment the grafts tended to decrease in size. Animals were sacrificed according to the following schedule: daily for 30 days; on the 46th day; each month for 11 months; and at 12 1/2 months after operation. Histological sections of 64 heads were examined for taste buds on the grafts.
During the first week after operation the tongue graft epithelium became thin and flattened, and there was considerable edema and necrosis in the epithelium and underlying tissues. The extent of these reactions varied in the different grafts. Two days after operation, 26 taste organs were present in one graft. Other clumps of cells which may be distorted organs were also noted. Between the 2nd and the 14th day, no taste organs were visible in the specimens examined.
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