Abstract
Neighboring pyramidal cells in the mouse cortex sometimes have different densities of dendritic spines. This was shown by a quantitative analysis of 10 neurons [by light microscopy]. For this, a method was worked out which corrects for the spines hidden behind (and in front of) the dendrite. There was a positive correlation between the spine densities on different parts of the dendritic tree of 1 neuron. The functional meaning of these findings was briefly discussed.