Absolutely, the cells can reprogram virtually instantaneously. In my culture experiments, some of the changes can start to occur in half a second (500 milliseconds). If I put 1000 cells in a culture dish and expose them to a broadcast energy signal, 1000 cells will respond instantaneously. However, if I expose them to a chemical signal, it will take longer for the chemical to reach and bind to the cells, creating a lag phase between the stimulus and the response.
For for information on the culture experiments click here: https://biologyofbelief.wordpress.com/2014/08/28/what-thoughts-and-emotions-are-affecting-your-cells-here-is-the-science-behind-it/
Or go to other topics: https://biologyofbelief.wordpress.com/topics-posted/