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dc.contributor.authorFraher, John P.en
dc.date.accessioned2018-01-31T11:44:02Z
dc.date.available2018-01-31T11:44:02Z
dc.date.issued1991en
dc.identifier.urihttp://hdl.handle.net/1842/28056
dc.description.abstracten
dc.description.abstractThe roots of certain cranial and spinal nerves are particularly suitable for studying the growth, myellnation and maturation of motoneuron fibres. Furthermore, their rootlets can be readily traced on serial sections in both PtJS and CHS. Accordingly, they were used for a series of morphometric studies analysing the developmental changes invloved in the segregation, growth, myellnation and maturation of central and peripheral segments of large and small motoneuron fibres (1-9). These included analysis of age changes in the internodal morphology of the entire myelin sheath of both the Schwann cell and the oligodendrocyte. This permitted comparison of the myelinogenic responses to stimuli emerging the same axon bundles, both within and between the two classes of ensheathing cell (5,6,8,9). Extensive statistical analysis was performed on ttie myelin sheath thickness - axon calibre relationship for the developing internodeB of large and small calibre motoneuron fibres (1,8,9). To test if this relationship was constant among all motoneuron fibre bundles, its setting was compared between nerves of similar developmental origin, peripheral distribution and function (10). The extent to which it varied between different levels along one and the same fibre bundle was also studied using dorsolateral vagal rootlets (14).en
dc.description.abstractA series of morphometric studies was performed on the developing CNS-PNS transitional zones of a number of rat cranial and spinal nerves to analyse the complex interaction, migration, and sometimes intermingling, of central and peripheral nervous tissues during this process (16-25). These contribute to understanding the wide variety of forms of the mature transitional zones (15,16,20-30), whether these lie at, peripheral to, or central to the plane of the CNS surface to which the nerve roots or rootlets which contain them are attached. CNS-PHS transitional node development was examined to assess the manner in which oligodendrocytes and Schwann cells modify their developmental behaviour in response to their unique relationship to one another in this location (20). These studies also examined the behaviour of myelinated and unmyelinated fibres as these pass between the CNS and PNS, whether they cross the interface between them once only (16-21, 24, 29), or alternate a number of times between the two tissue compartments (28). The morphology, Including myelin-axon relationships, of isolated islands of CNS tissue in the PNS (31) and of PNS tissue in the CNS (14, 28) was also examined quantitatively. All of these studies on the transitional zone, as well as one experimental study in particular (34) also dealt with its functional, especially mechanical properties.en
dc.description.abstractExtensive morphometric investigations were carried out to determine the maturationa1 changes in axons, myelin sheaths and the relationships between these, in rat mixed peripheral nerves (a) under control conditions (35) and (b) in animals in which diabetes mellitus had been experimentally induced (36).en
dc.description.abstractFollowing an earlier investigation (11) a detailed study was made of the age-related decrease in the degree of branching of rat cervical ventral root axons from birtti to adulthood, to determine the relative contributions of axon loss and Schwann cell proliferation to axon segregation (12). In another numerical study (13), the size of the autonomic component of the oculomotor nerve was estimated. Other developmental studies concerned macrophages related to developing ventral roots (32) and axon-glial relationships in the developing vomeronasal nerve (33).en
dc.publisherThe University of Edinburghen
dc.relation.isreferencedbyen
dc.subjectAnnexe Thesis Digitisation Project 2017 Block 16en
dc.titleMorphometric nerve studiesen
dc.typeThesis or Dissertationen
dc.type.qualificationlevelen
dc.type.qualificationnameDSc Doctor of Scienceen


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