Non-response of rough endoplasmic reticulum containing intracisternal microtubules to axotomy in the dog

Responses of the RER containing intracisternal microtubules in the canine ganglion nodosum to axotomy were observed at 3, 7, 14, 30, 50 and 99 days after section of the vago-sympathetic trunk. At 3 days, neurons showed no changes. From 7 days to 50 days, a retrograde reaction occurred in the cell bodies; nuclei were irregular in outline and eccentric in position and flattened RER disintegrated and dispersed. On the other hand, dilated RER containing intracisternal microtubules, which was detected as cytoplasmic inclusions under the light microscope, was present at the opposite pole to the eccentric nucleus. The ratio of areas of cytoplasmic inclusion to cell body significantly decreased. However, there were no changes in the size and arrangement of intracisternal microtubules within the RER. At 99 days, axotomized cell bodies had recovered and the RER containing intracisternal microtubules was indistinguishable from the contralateral controls. These findings indicate that the RER containing intracisternal microtubules is not disrupted by axotomy, though it is compactly packed at the periphery of cell bodies during the retrograde reaction. It appears, therefore, that the RER containing intracisternal microtubules does not respond to axotomy.