PARAMETERS OF FIXATION OF PUTATIVE PAIN AFFERENTS IN URETER - PRESERVATION OF DENSE CORES OF LARGE VESICLES IN AXONAL TERMINALS

  • 1 January 1976
    • journal article
    • research article
    • Vol. 122  (SEP) , 113-120
Abstract
The effect of a number of fixation procedures on the dense-cored vesicles in those axons in the ureteric plexuses which have recently been characterized as pain afferents was studied in the rat. Many of the terminals identified in material fixed by perfusion with glutaraldehyde contained few if any vesicles, and because of the loss of the microtubules, such terminals could not be satisfactorily differentiated after cold immersion fixation. Immersion fixation in glutaraldehyde produced changes in the number and distribution of the vesicles in the axons which accentuated the similarity of the vesicle containing regions to the terminals of purinergic axons. Few of the dense-cored vesicles present in glutaraldehyde fixed material were preserved by fixation in permanganate, osmium and paraformaldehyde, and the pattern of preservation of the vesicles by the various fixatives used was suggestive of major differences in the composition of their cores to those of the vesicles in the adrenergic axon. There was also evidence from the study of osmium fixed material that both the number and appearance of the vesicles can be affected by the type of buffer used, and the presence of more vesicles in the axons after fixation in veronal buffered osmium than in any of the other osmium fixed material was attributed to the membrane stabilizing properties of the buffer.