Magnitude, laterality, and uniformity of swelling in axotomized spinal motoneurons: lack of evidence for influence by the distal stump.
Injury to frog lumbar motor axons produces a coordinated, allometric enlargement of the nucleolus, nucleus, and cell body of the injured neuron. The mechanisms by which swelling is initiated and sustained are not known. In this study, we have sought evidence for a role of the severed distal stump in the magnitude, laterality, and uniformity of the swelling response in frog spinal motoneurons. We find that swelling of motoneuron nucleoli, nuclei, and perikarya after unilateral spinal nerve transection is exclusively ipsilateral and uniform among motoneurons of different sizes. Removal of the severed distal stump does not affect the magnitude, unilaterality, or uniformity of the swelling responses. Thus, the distal stump appears to play no role in initiating swelling following spinal nerve transection.
McIlwain
D L
DL
Curriculum in Neurobiology, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USA.
Hoke
V B
VB
D000818:Animals; D019771:Axotomy; D005260:Female; D008161:Lumbosacral Region; D008297:Male; D009046:Motor Neurons / Q000166:cytology*; D011894:Rana pipiens; D013127:Spinal Nerves / Q000166:cytology*