Location of preganglionic neurons is independent of birthdate but is correlated to reelin-producing cells in the spinal cord

Many studies suggest that during neuronal development the birthdate of a neuron appears to have significant consequences for its ultimate location and identity. Our past study shows that sympathetic preganglionic neurons (SPN) in mice lacking the reelin gene settle in abnormal positions in the spinal cord. In the present study we determined that birthdate is not a factor contributing to the abnormal position of SPN in reeler. In both normal and reeler mice the period of neurogenesis of SPN was similar, and the final location of SPN in the spinal cord was independent of birthdate. Additionally, we have identified at least two types of ventral interneurons, VI and V2, that are involved in the production of Reelin and the positioning of SPN in the spinal cord. (C) 2004 Wiley-Liss, Inc.