[Ultrastructural changes in the sympathetic axons, their synapses and lemmocytes of frogs resulting from anoxia]

Under anoxia, ultrastructural alterations were revealed in the cytoplasm of sympathetic axons and their synapses, and in lemmocytes in unmielinated bundles of the frog urinary bladder. Anoxia acts as a stimulator. Six minutes anoxia causes the amplification of activity of nerve bundle organoids: augmentation of the granular ER, the number of ribosomes and pinocytotic vesicles, and swelling of mitochondria in trunk and preterminal areas of nerve bundles in lemmocytes. In par distance synapses, small synaptic vesicles are modified, vacuoles are formed, and mitochondria get swollen; the cytoplasm of lemmocyte processes around the synaptic boutons is swollen, its fibrillar structures and part of ribosomes disappear. Under a prolonged anoxia, the number of ribosomes in nerve bundles is reduced, the mitochondria are getting more numerous but with lower electron density; the big dense cored vesicles are accumulated in synapses. After the frog death due to anoxia, deformation of part of the organoids is seen to accompany these changes.