Direction
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Direction |
Use to understand any preferred orientation in the dendritic processes. This type of projection eliminates many of the distortions related to depth foreshortening. |
Loss & distortion -- the torsion ratio
Torsion ratio = (Length of processes) / (Length of the processes after applying the fan in projection)
The Fan In projection displays the dendritic processes with some loss in length. The amount of loss is described by the tortuosity factor, or torsion ratio.
How it works
The Fan In projection begins by placing an axis through the neuron. The axis is always a vertical line.
Imagine attaching one edge of a sheet of paper to the axis. The sheet of paper is swept around the axis collecting tracings of the dendritic structures. After sweeping through a full 360 degrees the sheet has collected all of the dendritic structures that have been traced with all of the dendritic processes appearing on the same side of the axis.
The Fan In projection can be combined with the Polar Histogram to investigate any preferential orientation of the processes. The Polar Histogram of the fan in projection reduces the visual image of the Fan In into values that describe the amount of growth in a particular direction.
Glaser, E.M., MCMullen, N.T. (1984). The fan-in projection method for analyzing dendrite and axon systems. Journal of Neuroscience Methods, 12: 37-42.
Neurolucida Explorer 11 | MBF Science Support Center | Downloads