[Metric examinations on the development of apical dendrites of cortical pyramidal cells during the postnatal time in the rat].
1. It is explained the postnatal evolution of some selected features of Golgi-impregnated layer V pyramidal neurons in the rat sensorimotor cortex from the 1st to the 90th day after birth (13 stages) quantitatively. Especially it is reported about the development of the length and the quantity of apical main dendrites and of the apical lateral branches from the 1st to the 3rd order as well as the branching behaviour of the dendrites (free ends of dendrites, branching points, ramification index). 2. The evolution of mean length of apical dendrites is represented by a sigmoidal polygon trace - like the classic growing curve. 3. During the 3rd month of the postnatal life the lateral branches of the apical dendrites show a distinct growing increase relating to the mean values of the total length of dendrites, their quantity and the branching behaviour. This intensification of growth is in contrast to the growing stagnation of the apical main dendrites in this time. 4. From this point of view it is deduced that relating to the maturation of pyramidal cells - contrary to the papers of other writers and contrary to a previous private conception - albino rats in the age of 3 months do not are differentiated cortical completely. 5. The several marks of pyramidal dendrites do not form themselves in the same time but successively. The maturing process of new dendrites or dendrite branches is the base of significant increase of the length. 6. It seems, that the formation of dendritic "tree" takes place in growing batches. In this context there are discussed the correlations between the morphometric conceivable changes in the cortical pyramids and the accession of functions in the animal.
D000818:Animals; D002454:Cell Differentiation; D003712:Dendrites / Q000648:ultrastructure*; D008297:Male; D009474:Neurons / Q000166:cytology; D051381:Rats; D013003:Somatosensory Cortex / Q000166:cytology*; D013569:Synapses / Q000648:ultrastructure
Metrische Untersuchungen zur Entwicklung der apikalen Dendriten von corticalen Pyramidenzellen während der Postnatalzeit der Ratte.