An acute dose of 2000 Roentgens (R) of x-ray was delivered to the head and neck area of Sprague-Dawley rats. Groups of rats were sacrificed at 0, 3, 7, 14, 21 and 30 days after x-ray irradiation. Both general nerve staining and localization of cholinergic nerves by special staining of fungiform papillae were performed. No apparent change in number and distribution of nerve fibres were observed light microscopically within the fungiform papillae containing normal, degenerating and regenerating taste buds. Similarly, cholinesterase activity was present in all control and experimental groups. These preliminary findings do not support the theory that taste bud degeneration is due to x-ray irradiation causing damage to related nerve fibres. A theoretical model of taste bud degeneration after acute x-ray irradiation is proposed.