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Observations on the postnatal development of clarke's column in the kitten
Author(s) -
Smith Diane Elizabeth
Publication year - 1969
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.901350303
Subject(s) - biology , kitten , anatomy , neuroscience , spinal cord , dorsal column nuclei , afferent , axon , cats , computer science , embedded system
Studies on the postnatal development of Clarke's column were undertaken in order to ascertain if there were changes observed morphologically that would be compatible with the results so far reported both anatomically and physiologically on the afferent supply and the cerebellar end‐point of this system. The studies were carried out on the L.2 and L.3 segments of the spinal cord of kittens ranging in age from newborn to eight weeks. The principal staining methods employed were the Ha modification of the Golgi‐Cox, the Rasmussen technique for synapses, and Bodian's fiber stain. The sections were viewed using substage and reflected illumination. The most pertinent findings involved (1) the number of synapses and their distribution over the cell body and dendrites and (2) the number of stem dendrites and their orientation. There is an apparent lack of stainable synapses at birth, by eight days synaptic endings are present and by three weeks the entire cell is encrusted with two distinct types of synaptic end bulbs. Regarding the second point, a noticeable decrease was seen in the number of stem dendrites with a concomitant centripetal orientation of the dendritic tree in relation to the center of Clarke's column. The significance of these changes on the maturation of Clarke's column, on its afferent input and on the development of the dorsal spinocerebellar tract as a functional system is discussed.