Changing CPM/Interaction/Contact value during simulation runtime

[Morpheus users]

Is it possible to change the value of cell type interactions in the CPM plugin during the simulation. For example the interaction between 2 cell types decrease from 10 to 0 over a period of 10 hours? One solution is to explicitly change the cell type and write pairwise interaction strengths for each cell type. This seems overly cumbersome. Is there a better solution to this?

Thanks

[Walter de Back]

Is it possible to change the value of cell type interactions in the CPM plugin during the simulation.

Yes, you can use interaction plugins including HomophilicAdhesion and HeterophilicAdhesion, see CPM/Interaction/Contact/HomophilicAdhesion.

In the attached model (based on the CPM/CellSorting_2D.xml example in Morpheus 1.2), a cell Property "c" (for cadherin) is created and this is used as a symbol for the adhesive in HomophilicAdhesion for the Contact between the celltpes ct1 and ct2. The value of "c" is changed by the Equation:

  c = sin(time / 1000.0) + 1 

which modulates cell-cell adhesion as a function of time according to a sine wave. 

As a result, the cell types ct1 and ct2 will sort out, then mix, sort out again, mix etc. See the attached video (.mp4). 

Steps to reproduce:

1. Define a symbol for time, e.g. Time / TimeSymbol = "time" 

2. Define a cell Property, e.g. "c". Note that this needs to be defined for all cell types.

3. Define an Equation (in one of the cell types) that changes "c" as a function of "time".

4. Add an adhesion plugin in CPM/Interaction/Contact/HomophilicAdhesion and with nonzero strength and use "c" as an adhesive.