Injury and restoration of structure in interneuronic synapses following total-body X-ray exposure

Abstract

Vol. 51, No. 1, pp. 102-105, January, 1961 Original article submitted February 15, 1960 In the morphological works devoted to the study of the reactions of the nervous system to the action of penetrating radiation, the state of the interneuronic synapses in these conditions has received little study. We know at present that synapses are altered after irradiation [5,6,7], but in the conducted works the state of the synapses in relation to the dose and the time elapsing after the action of ionizing radiation was not investigated. The restoration of the synapses in animals surviving after exposure has not been studied either.Our aim in this work was to discover the initial changes in the state of synapses due to a single exposure of animals to small, medium, and large doses ofx rays, and to trace these changes to the climax of the process and after its completion. Experimental MethodWe studied the synapses in the superior cervical sympathetic ganglia of cats irradiated on the RUM-11 apparatus with doses 30,100,500, and 1200 r, at voltage 200 kv, current 15 mA, no fitters, and at a distance of 65 cm from the anticathode. The dose rate was about 16 r/rain.In order to check the state of the animats, we made analysis of their blood before irradiation and at different times after irradiation.The experimental cats (48 animals) were divided into four equal groups. The animals in each group were irradiated with a single dose and sacrificed (in pairs) at different times after irradiation (see table).To reveal the synapses in the ganglia, we used the Bielschowsky-Gros-Lawrentjew and the Golgi-Deineka methods. In order to compare these methods, we treated the left ganglia by the first method and the right ganglia by the second method in every case. Immediately after the animals were chloroformed we extracted the ganglia and fixed them for 1 89 hr in AFA fluid. We then transferred the left ganglia to 20% neutral formalin for subsequent treatment by the Bielschowsky-Gros-Lawrentjew method, and the right ganglion to a 3% silver nitrate solution for study by the Golgi-Deineka method. Experimental ResultsWe were able to establish the normal structure of the synapses in the superior cervical ganglion of the cat from our own observations [2,3] and the information in the literature [4,5,7]. 100