Biomaterial Database

Ultrastructural study of degeneration and regeneration in the amphibian tectum. 1979

A Ostberg, and J Norden

The processes of degeneration and reinnervation in the optic tectum of Xenopus laevis have been detailed by quantitative ultrastructural analysis. The tecta were denervated either permanently, by removing the contralateral eye, or temporarily, by cutting the optic tract. After denervation the total number of synapses decreases rapidly within 4 days of a stable level of about 40% of the original number. Vacated postsynaptic sites are subsequently removed by phagocytosis. When regenerating axons arrive in the tectum they make synaptic contact by inducing new postsynaptic membrane specializations. The ultrastructural sequence of reinnervation by optic axons resembles initial synaptogenesis.

UI	MeSH Term	Description	Entries
D009410	Nerve Degeneration	Loss of functional activity and trophic degeneration of nerve axons and their terminal arborizations following the destruction of their cells of origin or interruption of their continuity with these cells. The pathology is characteristic of neurodegenerative diseases. Often the process of nerve degeneration is studied in research on neuroanatomical localization and correlation of the neurophysiology of neural pathways.	Neuron Degeneration,Degeneration, Nerve,Degeneration, Neuron,Degenerations, Nerve,Degenerations, Neuron,Nerve Degenerations,Neuron Degenerations
D009416	Nerve Regeneration	Renewal or physiological repair of damaged nerve tissue.	Nerve Tissue Regeneration,Nervous Tissue Regeneration,Neural Tissue Regeneration,Nerve Tissue Regenerations,Nervous Tissue Regenerations,Neural Tissue Regenerations,Regeneration, Nerve,Regeneration, Nerve Tissue,Regeneration, Nervous Tissue,Regeneration, Neural Tissue,Tissue Regeneration, Nerve,Tissue Regeneration, Nervous,Tissue Regeneration, Neural
D009900	Optic Nerve	The 2nd cranial nerve which conveys visual information from the RETINA to the brain. The nerve carries the axons of the RETINAL GANGLION CELLS which sort at the OPTIC CHIASM and continue via the OPTIC TRACTS to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the SUPERIOR COLLICULI and the SUPRACHIASMATIC NUCLEI. Though known as the second cranial nerve, it is considered part of the CENTRAL NERVOUS SYSTEM.	Cranial Nerve II,Second Cranial Nerve,Nervus Opticus,Cranial Nerve, Second,Cranial Nerves, Second,Nerve, Optic,Nerve, Second Cranial,Nerves, Optic,Nerves, Second Cranial,Optic Nerves,Second Cranial Nerves
D010587	Phagocytosis	The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).	Phagocytoses
D003712	Dendrites	Extensions of the nerve cell body. They are short and branched and receive stimuli from other NEURONS.	Dendrite
D003714	Denervation	The resection or removal of the nerve to an organ or part.	Laser Neurectomy,Neurectomy,Peripheral Neurectomy,Radiofrequency Neurotomy,Denervations,Laser Neurectomies,Neurectomies,Neurectomies, Laser,Neurectomies, Peripheral,Neurectomy, Laser,Neurectomy, Peripheral,Neurotomies, Radiofrequency,Neurotomy, Radiofrequency,Peripheral Neurectomies,Radiofrequency Neurotomies
D004292	Dominance, Cerebral	Dominance of one cerebral hemisphere over the other in cerebral functions.	Cerebral Dominance,Hemispheric Specialization,Dominances, Cerebral,Specialization, Hemispheric
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001369	Axons	Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.	Axon
D012683	Sensory Deprivation	The absence or restriction of the usual external sensory stimuli to which the individual responds.	Deprivation, Sensory,Deprivations, Sensory,Sensory Deprivations