Ultrastructural changes in the dorsal motor nucleus of monkey following bilateral cervical vagotomy
- 1 February 1986
- journal article
- conference paper
- Published by Springer Nature in Journal of Neurocytology
- Vol. 15 (1), 1-15
- https://doi.org/10.1007/bf02057900
Abstract
The neurons of the dorsal motor nucleas (DMN) of the monkey (Macaca fascicularis) were of two main types: small (13 × 8 μm) and medium-sized (20 × 13 μm). The latter, which were the predominant form, contained a pale oval nucleus surrounded by organelle-rich cytoplasm. Between one and three long principal dendrites per section profile arose from eac1 of the somata. Both axosomatic and axodendritic synapses were seen on these cells although the latter were more common. No structural changes were noted in the DMN 1–3 days after bilateral cervical vagotomy. Some of the dendrites of the medium-sized axotomized vagal neurons appeared darkened 5–10 days after the operation. With longer surviving intervals, i.e. 21 and 28 days after operation, darkened dendrites were more commonly seen and the cytoplasmic density of these dendrites was dramatically enhanced. Their mitochondria were pale and some of them also showed vesiculation. Both normal and degenerating axon terminals were seen to form synaptic contacts with the darkened dendrites. The degenerating axon terminals were characterized by the clumping of their round agranular vesicles. Both darkened dendrites and degenerating axon terminals were phagocytosed by hypertrophied astrocytes and activated microglial cells. Blood elements infiltrating into the DMN were a possible source for some of the neural macrophages. It was concluded from the present study that the dendrites of the vagal neurons were the first structures to degenerate in axotomy and these were subsequently removed by glial elements. Degenerating axon terminals on the darkened dendrites could represent endings of the central processes of peripheral vagal ganglion cells that had undergonetransganglionic degeneration after damage to their peripheral processes.This publication has 37 references indexed in Scilit:
- Brain stem projections of sensory and motor components of the vagus complex in the cat: II. Laryngeal, tracheobronchial, pulmonary, cardiac, and gastrointestinal branchesJournal of Comparative Neurology, 1980
- Neurons of origin of cervical vagus nerves in the rat and monkeyBrain Research, 1980
- An autoradiographic examination of the central distribution of the trigeminal, facial, glossopharyngeal, and vagal nerves in the monkeyJournal of Comparative Neurology, 1979
- An ultrastructural study of transganglionic degeneration in the main sensory trigeminal nucleus of the ratJournal of Neurocytology, 1979
- Nerve cell degeneration and death in the trigeminal ganglion of the adult rat following peripheral nerve transectionJournal of Neurocytology, 1978
- Qualitative and quantitative study of synaptic displacement in chromatolyzed spinal motoneurons of the catJournal of Comparative Neurology, 1978
- Transganglionic degeneration in trigeminal primary sensory neuronsBrain Research, 1975
- Ultrastructure of Axonal Reaction in Red Nucleus of CATJournal of Neuropathology and Experimental Neurology, 1975
- ULTRASTRUCTURE OF RETROGRADE DEGENERATION IN THALAMUS OF RAT 1. NEURONAL SOMATA DENDRITESJournal of Neuropathology and Experimental Neurology, 1973
- Autoradiographic Studies on Histogenesis of Brain Macrophages in the MouseJournal of Neuropathology and Experimental Neurology, 1972