Polar histogram

The polar histogram describes the overall direction of dendritic growth.

  • The growth is displayed in the form of a round directional histogram that uses pie shaped wedges to describe values (unlike the traditional histogram that uses rectangles to describe values).
  • Length is plotted as a function of direction.

The meaning of length in polar histograms is important: Projection collapses Z, but length in Z is used in the length calculation for the polar histogram. The total length in the polar histogram is the same as the total length of all processes used in the polar histogram analysis.

The polar histogram is not affected by translation. If several processes are included in the analysis, then the relative position of the processes is unimportant.

 

Reference

McMullen, N.T., Glaser, E.M., and Tagamets, M (1984). Morphometry of spine-free nonpyramidal neurons in rabbit auditory cortex. Journal of Comparative Neurology 222:383-395.