Growth of the initial dendrite of early differentiated interneurons in the zona intermedia of the embryonic chick cervical cord: A morphometric study with the Golgi method

Abstract

From stages 24 to 45 of the chick embryo, the longest dendrite of each interneuron in the zona intermedia was measured in the upper cervical cord prepared by the Golgi method, the measuring being done exclusively on the large neurons at each stage to follow the dendritic growth of neurons homogeneous in their time of origin. The longest dendrite grew at a rate of 92–184 μm per day at stage 24, and thereafter its growth rate gradually slowed down to 4 μm per day at stage 36. Already at stage 27, the interneurons located deep in the mantle layer reached with their longest dendrite the marginal layer which was the site of synaptic contact in early developmental stages. Thus, the initial rapid growth of the dendrite could be regarded as highly effective for the early formation of synaptic contact.