| ... | ... | @@ -74,4 +74,8 @@ | 
              
                    | 74 | 74 | **Level**: advanced(%%)  **Type**: interactive tutorial | 
              
                    | 75 | 75 |  | 
              
                    | 76 | 76 | In this tutorial you will learn how to implement cell signalling function in the reaction-diffusion system by characterising your problems by the answers to three questions: (1) Where do the dynamics occur, (2) Who are the actors, and (3) How do they interact? | 
              
                    |  | 77 | +=== [[Ball and Stick model part 3>>https://neuron.yale.edu/neuron/docs/ball-and-stick-model-part-3||rel=" noopener noreferrer" target="_blank"]] === | 
              
                    | 77 | 77 |  | 
              
                    |  | 79 | +**Level**: advanced(%%)  **Type**: user documentation | 
              
                    |  | 80 | + | 
              
                    |  | 81 | + |