Literary Notices. iii 



Micro-Chemical Alterations in Nerve Cells,^ 



This paper undertakes the study of functional changes in nerve 

 cells from the stand point of micro-chemical analysis of the intra- 

 cellular metabolic products and their qualitative and quantitative 

 alterations. 



The research was conducted upon the spinal ganglion cells of the 

 rabbit, the seventh lumbar segment being especially chosen because it 

 receives the greater part of the fibers from the sciatic nerve. The 

 difficulty was to secure for a sufficient length of time absolute rest of 

 the nervous elements — thus preventing the formation of new meta- 

 bolic products — and at the same time to keep the cells alive, so that 

 they might eliminate those produced. To this end the sciatic nerve 

 was resected and the animal kept alive two days thereafter. Fatigue 

 on the other hand was produced by exciting the sciatic nerve with a 

 Du Bois-Reymond apparatus, the excitation lasting from 30 minutes 

 to 8 hours. The ganglia were then as quickly as possible treated with 

 the fixing reagent, and for this purpose Hermann's fluid was selected 

 as it best preserves both the granules and the cytoplasmic structures. 

 The sections were stained variously, chiefly in acid fuchsin decolor- 

 ized with picric acid and methyl green. 



The author, following Lugaro, agrees with Flemming in finding 

 the cytoplasmic structure distinctly filar, the threads being brought 

 out clearly by the methyl green and lying among rather large masses 

 of dense protoplasm which appear homogeneous and react to the stain 

 like the threads. Besides these masses, there were sparse and very 

 minute granules which resist the action of the decolorizer and there- 

 fore appear red. These fuchsinophile granules were the objects of spec- 

 ial study. Tn normal cells, i. e. those removed from from the body by 

 vivisection, they occur in the clear interfilar spaces and are occasion- 

 ally elongated. They occur in less abundance in the vacuolar spaces 

 of the nucleus. 



After resection of the sciatic nerve and consequent rest, i. e. after 

 long freedom from stimuli, the size of the fuchsinophile granules was 

 reduced ; in some elements they could not be found at all. 



After excitation of the sciatic nerve for half an hour there was a 

 conspicuous increase of the granules, as compared with the ganglia 

 removed by vivisection. The nucleus is without granules. If the ex- 

 citation is prolonged for two hours, the number of the granules greatly 



^ Levi, G. Contributo alia fisiologia della cellula nervosa. Rivista di 

 Fatal. Nervosa e Mentale^ I, 5, May, 1896. 



