THE SILVER DIAMMINE ION STAINING OF PERIPHERAL NERVE ELEMENTS AND THE INTERPRETATION OF THE RESULTS: WITH A MODIFICATION OF THE BIELSCHOWSKY-GROS METHOD FOR FROZEN SECTIONS

¹ The Histology Division, Institute of Physiology, University of Glasgow

1. A modification of the Bielschowsky-Gros silver diammine ion (ammoniacal silver) method of staining frozen sections is given in detail. This method has been extensively used in the study of peripheral innervations and has given good results. Examples of these are figured. The method has the great advantages of (a) giving good results both after short and very long periods of formalin fixation, (b) allowing microscopic control of the actual staining process, and (c) permitting completely finished specimens to be made in one day after fixation is complete.

2. A short discussion of the rationale of this type of silver staining is given.

3. The interpretation of the results of silver-staining methods is discussed, and a plea is made for trying to build up a complete picture from a series of varying impregnations of peripheral innervations. Such a series is illustrated for the sympathetic ground plexus. It is suggested that this plexus has few "end-points", and that humoral substances may be released in the continuity of the strands from the "beads" on the finest fibrils.

Note:

To Professor R. C. Garry for his constant interest and encouragement we gladly express our thanks. To Mr. S. D. Morrison for his many helpful suggestions we are also indebted, and to Dr. George Thomson of the Department of Chemistry of this University we are deeply grateful for much help in the chemistry of the method.

The photomicrographs are the work of Mr. D. Macallister, and for these and his unfailing helpfulness we acknowledge our indebtedness.

Mr. A. R. Jamieson, City Analyst, Corporation of Glasgow, has kindly given figures for the Glasgow tap water from Loch Katrine source. We are indebted to him for his helpful co-operation.

Part of the expenses of the work on which this paper is based were paid from the Rankin Medical Research Fund. We would like to express our thanks for this assistance.