Fractal analysis of dendrite morphology of rotated neuronal pictures: the modified box counting method.

The fractal dimension of a non-stellate neuron changes continuously with rotation of the neuronal picture. For a stellate neuron such changes cannot be noticed. During preprocessing for the box counting, non-stellate neurons should be arranged so that the major diameters of their dendrite fields are parallel. It was shown that a non-stellate neuronal picture had the smallest box dimension when the angle between the horizontal or vertical axis and its major diameter was about 45 degrees. The box counting method which uses ImageJ software does not consider the position of a picture on the computer's screen. A dispersion of the box dimension values of a sample is generally rather large so that their mean value is with larger standard deviation. Modified box counting method partly diminishes these findings. To improve a dependence on neuronal rotation for the box counting dimension of nonstellate neurons, prior to applying the box counting, the non-stellate neurons should be arranged so that the major diameters of their dendrite fields are parallel.