The Development of the Rat Spinal Cord

ISBN-13: 9783540131199 / Angielski / Miękka / 1984 / 168 str.

Joseph Altman; Shirley A. Bayer

Opis

The study of the development of the spinal cord has a relatively long history. The spinal cord was singled out as a favorable site when cytological techniques were first applied to the study of the embryonic development of the nervous system. Bidder and Kupffer (1857), using the new procedure of hardening nerve tissue with chromic acid (Hannover 1844), made an investigation of spinal cord development in fetal sheep. They reported that the cellular central mass of the spinal cord develops before its fibrous envelope, deducing from this that the fibers of the white matter of the embryonic spinal cord were outgrowths of cells in the gray matter. Bidder and Kupffer also noted that in the spinal ganglia fibers grew out from cells in both directions, peripherally and centrally. Their report was one of the earliest ontogenetic lines of evidence in support of the later-formulated neuron doctrine (Waldeyer 1891). The spinal cord re- mained a favorite topic of morphogenetic studies of the nervous system through- out the last quarter of the nineteenth century, with seminal contributions made by His (1886, 1889), von Lenhossek (1889), Retzius (1898), and Ramon y Cajal (1960). Indeed, the preoccupation with the spinal cord in the early investigations of neural development had a lasting, and to some extent regrettable, influence on ideas about the ontogeny of the brain and on the terminology adopted by anatomists.

Spis treści

1 Introduction.- 2 Materials and Methods.- 2.1 Whole-Body Long-Survival (Late Fetal) Thymidine Radiograms.- 2.2 Spinal Cord Long-Survival (Adult) Thymidine Radiograms.- 2.3 Whole-Body Short Survival Thymidine Radiograms.- 2.4 Methacrylate-Embedded Embryos.- 3 A Survey of the General Features of the Spinal Cord and Its Development.- 3.1 Organization of the Spinal Cord.- 3.2 Development of the Spinal Cord.- 4 Development of Motor Neurons and the Growth of Ventral Root Fibers.- 4.1 Time of Production of Large Motor Neurons.- 4.2 Maturation and Columnar Segregation of Motor Neurons.- 4.3 Growth of Motor Fibers and Their Penetration into Somites and Limb Buds.- 4.4 Time of Origin and Maturation of the Preganglionic Motor Neurons.- 5 Development of Sensory Neurons and Growth of the Dorsal Root System.- 5.1 Time of Origin of Dorsal Root Ganglion Cells.- 5.2 Sites of Origin of the Dorsal Root Ganglia and the Spinal Boundary Caps.- 5.3 Maturation of the Dorsal Root Ganglia and of the Boundary Caps.- 5.4 Segmentation of the Boundary Caps and Dorsal Root Ganglia and the Growth of Distal Sensory Fibers.- 5.5 Growth of the Dorsal Root Fibers and of the Dorsal Funiculus.- 6 Development of Relay Neurons: The Contralaterally and Ipsilaterally Projecting Cells.- 6.1 Time of Origin of Contralaterally and Ipsilaterally Projecting Relay Neurons.- 6.2 Transverse Microsegments of the Contralaterally and Ipsilaterally Projecting Relay Neurons.- 6.3 Identity and Settling Patterns of the Sequentially Produced Relay Neurons.- 7 Development of the Interneurons of the Dorsal Horn.- 7.1 Time of Origin and the Settling of the Interneurons of the Dorsal Horn.- 7.2 Time of Origin of the Interneurons of the Dorsomedial Gray.- 8 Development of Some Glial Components of the Spinal Cord.- 9 General Discussion.- 9.1 Development of the Transverse Organization of the Spinal Cord with Some Functional Considerations.- 9.2 Development of the Longitudinal Organization of the Spinal Cord with Some Functional Considerations.- 9.3 Some Guidance Mechanisms in the Growth of Spinal Afferents and Afferents.- 10 Summary.- 11 References.- 12 Subject Index.