Image Colored Cells (IMAGE) Karolinska Institutet Caption The generation of the many different types of nerve cells is controlled early during embryogenesis, where distinct pools of precursor cells express distinct combinations of genes that control neuronal fate. In this illustration from an embryonic mice spinal cord, precursor cells were labeled by a different color depending on the gene they express. Using modern mice genetics, the authors have ablated specific subgroups of those precursors cells and unveiled the neuronal circuitries that control left-right hindlimb coordination during walking. Credit Credit: Ole Kiehn and colleagues, <i>Nature</i> June 2013 Usage Restrictions This image may only be published in connection to news reports about the current findings (<i>Nature</i>, June 30, 2013). License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.