VARIATIONS IN THE AXON REACTION AFTER DIFFERENT TYPES OF NERVE LESION - LIGHT AND ELECTRON-MICROSCOPIC STUDIES ON THE FACIAL NUCLEUS OF THE RAT

  • 1 January 1981
    • journal article
    • research article
    • Vol. 110  (2) , 173-188
Abstract
Retrograde nerve cell reaction was studied after evulsion, transection and crush lesion of the facial nerve in rats. Crush lesion caused barely discernible light microscopic and EM changes. The Nissl bodies became slightly smaller than normal and the arrangement of the granular endoplasmic reticulum (rER) somewhat more irregular. The crush lesions were followed by complete functional and morphologic recovery. After nerve evulsion, the cells showed severe chromatolysis, nuclear caps, nuclear eccentricity and folding of the nuclear membrane. Ultrastructurally there was a dispersion of the rER and formation of laminated dense bodies. Later, the rER was partly degranulated and some of the polyribosomes dissociated. These neurons ultimately disappeared. Transection of the nerve caused an intermediate axon reaction and a moderate loss of neurons. Certain neurons may regenerate after axotomy in spite of minimal light microscopic and EM changes in the nerve cell bodies. The same neurons may show the typical axon reaction after more severe nerve injuries. Mechanisms which may be involved in the regulation of the retrograde nerve cell reaction after axotomy are briefly discussed.

This publication has 1 reference indexed in Scilit: