Open delineations

Many neurons in the cortex extend across several cortical layers. Delineations, or open contours, can be used as a framework for measuring the proportions of neurons in different layers:

1. Create delineations to indicate layers in the tracing.
2. Analyze the layers with the Layer Length analysis in Neurolucida Explorer.

Creating delineations: procedure

1. Trace delineation lines.
   1. Select the Contour tracing mode.
   2. Trace contours along the top and bottom of each layer.
   3. Right-click and select End open contour.
   4. Repeat steps b-c until all layers have an open contour at their top and bottom.
2. Go to Trace > Edit and click Select objects.
3. Select the two lines that delineate a layer: Click the first line then hold down the Shift key and click the second line.
4. Right-click and select Define open delineation to open the Open Delineation Name window.
   1. Type a name and click OK. The name will be used as the layer name when using the Layer Length Analysis in Neurolucida Explorer.
   2. The delineated layer is represented with dashed lines.

      To undo the delineations, select the delineation lines again,right-click with your mouse and select Remove open delineation.

5. Repeat steps 3-4 until all layers are defined.