Comparison between the dimensions of dendritic spines in the cerebral cortex of newborn and adult guinea pigs.

Dendritic spines in the cerebral cortex of newborn and adult guinea pigs were compared quantitatively. An increase in the average diameter of the head by 21% and in the diameter of the stalk by 29% was found. No difference could be measured in the average length of the spines of both age groups. When plotting the individual measurements against each other, a slight correlation could be found only between the size of the spine head and the thickness of the stalk.