Some research
http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum
indicates that anabolic steroids markedly stimulate the proliferation of satellite cells into muscle cells, which increases the number of nuclei within a muscle cell and enhances its capacity to grow. They also stimulate the growth of new muscle cells more intensively than normal training. In theory, you should be able to gain all the lost muscle back naturally, although it could last longer.
In fact, a steroid cycle that has increased the number of nuclei within a muscle cell should enhance your potential as a whole. You should be able to continue in your gains for a certain time naturally.