Alterations in the postnatal development of the cerebellar cortex due to zinc deficiency. III. Impaired dendritic differentiation of basket and stellate cells.

The effects of zinc deficiency and undernutrition on the dendritic differentiation of basket and stellate cells were studied in 21-day-old rats. A morphometric analysis of the dendritic branching of basket and stellate neurons was used that took into account the cell's position in the molecular layer. Zinc deficiency and undernutrition during the suckling period impaired the dendritic differentiation of cerebellar basket and stellate cells. The effects of zinc deficiency were not due totally to the reduced food intake of lactating dams. In the lower 65-75% of the molecular layer of zinc-deficient (ZD) pups, the dendritic field area, the total dendritic length and the number of branches per interneuron were reduced by 45-61%. In the lower 50-60% of the molecular layer, undernutrition reduced the dendritic field area, the total dendritic length and the number of branches per neuron by 32-44%. A comparison of ZD and undernourished (pair-fed) pups indicated that the dendritic field area and total dendritic length of neurons of ZD animals were 43% and 30% smaller in the lower half of the molecular layer. The number of branches per neuron was not significantly different between ZD and undernourished animals. The area of the soma was unaffected by dietary treatment. A delay in the onset of dendritic differentiation and a retarded rate of dendritic growth were considered possible mechanisms for the impaired dendritic differentiation.