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          DISABLE/ENABLE CELLS & SYNAPSES

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To disable a cell or a synapse, click on it.  To re-enable it,
click on it again.  

Cells turn dark gray when they are disabled, and are green when
they are enabled.  The variables in disabled cells are frozen,
but they will continue to produce the same synaptic current as
they did the instant before they were disabled.  We recommend
disabling the connections going away from any disabled cells to
totally remove their contribution.

Synapses turn white when disabled, and are black when enabled.
When a synapse is re-enabled, it takes the value it had before
it was disabled.  If one disables a synapse and then edits its
synaptic weight in the Parameter Editor, the synapse will 
automatically be re-enabled and will take the value specified
in the Parameter Editor.