Post-hatch development of dendritic arborization in cerebellar Purkinje neurons of quail chicks: a morphometric study

To study development of the cerebellum in precocial birds during the early post-hatch period, dendritic arborization of Purkinje neurons was analyzed by intracellular Lucifer-yellow filling in fixed slices. Purkinje neurons were sampled from parasagittal slices of the cerebellar vermis of quail chicks (from 1 day pre-hatch to 14 days post-hatch). Confocal images revealed that the dendritic arborization expanded two-fold during the initial 3 days post-hatch, whereas the growth of cell bodies was much smaller. The dendritic expansion was accompanied by significant elongation of distal dendritic segments (5th and more distal segments), while the length of proximal dendrites (1st-4th segments) and the number of dendritic branches remained unchanged. Active synaptogenesis may occur selectively in distal dendrites during the early post-hatch period.