Biomaterial Database

Development of terminals and synapses in laminae I and II of the rat medullary dorsal horn after infraorbital nerve transection at birth. 1997

J P Golden, and J A Demaro, and P L Robinson, and M F Jacquin

Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.

Infraorbital nerve damage at birth kills neurons and alters anatomical, physiological, and biochemical properties of surviving cells in all portions of the trigeminal brainstem complex, with the exception of laminae I and II of the medullary dorsal horn. The resiliency of laminae I and II may be due to rapid terminal sprouting and reactive synaptogenesis in this region. To test this hypothesis, quantitative electron microscopy revealed the types and numbers of terminals, synapses, and degenerating and growth cone-like profiles in the left laminae I and II at 1, 4, 17, and 90 days after left infraorbital nerve section. Control data were derived from normal newborns and from the right laminae I and II and the left infraorbital nerve of every experimental animal. Deafferented laminae I and II contained a median of 11.7, 8.2, 21.8, and 38.2 synapses/100 microm3 on days 1, 4, 17, and 90, respectively. At corresponding ages, there were 17.1, 19.4, 36.2, and 32 terminals; 14.4, 4.2, 5.1, and 0.3 degenerating profiles; and 4.6, 2.2, 0.1, and 0 growth cone-like profiles/100 microm2. Significant differences from the control right side are: 1) The percentage area occupied by terminals is less on days 1 and 17; 2) terminal density does not increase from day 0 to day 4 as it does on the control side; 3) the density of degenerating profiles is higher on day 17; 4) growth cones are less dense on days 4 and 17; and 5) synapse density is lower on days 1 and 4. Axon number in the infraorbital nerve was highly predictive of terminal and synapse densities in deafferented laminae I and II at all ages. Thus, in laminae I and II, 1) the time course and nature of development are altered by deafferentation at birth; 2) reorganization of terminals and synapses occurs within a day of the lesion; 3) by day 90, there are no remaining lesion effects; and 4) the status of the injured nerve predicts central terminal and synapse densities. These are signs of injury-induced transganglionic degeneration and sprouting. The source of the latter is unknown, although areal fraction data suggest that "replacement" terminals may not be of primary afferent origin.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008526	Medulla Oblongata	The lower portion of the BRAIN STEM. It is inferior to the PONS and anterior to the CEREBELLUM. Medulla oblongata serves as a relay station between the brain and the spinal cord, and contains centers for regulating respiratory, vasomotor, cardiac, and reflex activities.	Accessory Cuneate Nucleus,Ambiguous Nucleus,Arcuate Nucleus of the Medulla,Arcuate Nucleus-1,External Cuneate Nucleus,Lateral Cuneate Nucleus,Nucleus Ambiguus,Ambiguus, Nucleus,Arcuate Nucleus 1,Arcuate Nucleus-1s,Cuneate Nucleus, Accessory,Cuneate Nucleus, External,Cuneate Nucleus, Lateral,Medulla Oblongatas,Nucleus, Accessory Cuneate,Nucleus, Ambiguous,Nucleus, External Cuneate,Nucleus, Lateral Cuneate
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
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
D009473	Neuronal Plasticity	The capacity of the NERVOUS SYSTEM to change its reactivity as the result of successive activations.	Brain Plasticity,Plasticity, Neuronal,Axon Pruning,Axonal Pruning,Dendrite Arborization,Dendrite Pruning,Dendritic Arborization,Dendritic Pruning,Dendritic Remodeling,Neural Plasticity,Neurite Pruning,Neuronal Arborization,Neuronal Network Remodeling,Neuronal Pruning,Neuronal Remodeling,Neuroplasticity,Synaptic Plasticity,Synaptic Pruning,Arborization, Dendrite,Arborization, Dendritic,Arborization, Neuronal,Arborizations, Dendrite,Arborizations, Dendritic,Arborizations, Neuronal,Axon Prunings,Axonal Prunings,Brain Plasticities,Dendrite Arborizations,Dendrite Prunings,Dendritic Arborizations,Dendritic Prunings,Dendritic Remodelings,Network Remodeling, Neuronal,Network Remodelings, Neuronal,Neural Plasticities,Neurite Prunings,Neuronal Arborizations,Neuronal Network Remodelings,Neuronal Plasticities,Neuronal Prunings,Neuronal Remodelings,Neuroplasticities,Plasticities, Brain,Plasticities, Neural,Plasticities, Neuronal,Plasticities, Synaptic,Plasticity, Brain,Plasticity, Neural,Plasticity, Synaptic,Pruning, Axon,Pruning, Axonal,Pruning, Dendrite,Pruning, Dendritic,Pruning, Neurite,Pruning, Neuronal,Pruning, Synaptic,Prunings, Axon,Prunings, Axonal,Prunings, Dendrite,Prunings, Dendritic,Prunings, Neurite,Prunings, Neuronal,Prunings, Synaptic,Remodeling, Dendritic,Remodeling, Neuronal,Remodeling, Neuronal Network,Remodelings, Dendritic,Remodelings, Neuronal,Remodelings, Neuronal Network,Synaptic Plasticities,Synaptic Prunings
D009475	Neurons, Afferent	Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.	Afferent Neurons,Afferent Neuron,Neuron, Afferent
D009915	Orbit	Bony cavity that holds the eyeball and its associated tissues and appendages.	Eye Socket,Eye Sockets,Orbits,Socket, Eye,Sockets, Eye
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
D005260	Female		Females
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