Many studies have reported the contribution of bone marrow-derived cells (BMDC) to the CNS, raising the possibility of using them as a new source to repair damaged brain tissue or restore neuronal function. This process has mainly been investigated in the cerebellum, in which a degenerative
microenvironment has been suggested to be responsible for its modulation. The present study further analyzes the contribution of BMDC to different neural types in other adult brain areas, under both physiological and neurodegenerative conditions, together with the mechanisms of plasticity
involved. We grafted genetically marked green fluorescent protein/Cre bone marrow in irradiated recipients: a) the PCD (Purkinje Cell Degeneration) mutant mice, suffering a degeneration of specific neuronal populations at different ages, and b) their corresponding healthy controls.
These mice carried the conditional lacZ reporter gene to allow the identification of cell fusion events. Our results demonstrate that BMDC mainly generate microglial cells, although to a lesser extent a clear formation of neuronal types also exists. This neuronal recruitment was not
increased by the neurodegenerative processes occurring in PCD mice, where BMDC did not contribute to rescuing the degenerated neuronal populations either. However, an increase in the number of bone marrow-derived microglia was found along the life span in both experimental groups. Six weeks
after transplantation more bone marrow-derived microglial cells were observed in the olfactory bulb of the PCD mice compared to the control animals, where the degeneration of mitral cells was in process. In contrast, this difference was not observed in the cerebellum, where Purkinje cell degeneration
had been completed. These findings demonstrated that the degree of neurodegenerative environment can foster the recruitment of neural elements derived from bone marrow, but also provide the first evidence that BMDC can contribute simultaneously to different encephalic areas through different
mechanisms of plasticity: cell fusion for Purkinje cells and differentiation for olfactory bulb interneurons.
Cell Transplantation publishes original, peer-reviewed research and review articles on the subject of cell transplantation and its application to human diseases. To ensure high-quality contributions from all areas of transplantation, separate section editors and editorial boards have been established. Articles deal with a wide range of topics including physiological, medical, preclinical, tissue engineering, and device-oriented aspects of transplantation of nervous system, endocrine, growth factor-secreting, bone marrow, epithelial, endothelial, and genetically engineered cells, among others. Basic clinical studies and immunological research papers are also featured. To provide complete coverage of this revolutionary field, Cell Transplantation will report on relevant technological advances, and ethical and regulatory considerations of cell transplants. Cell Transplantation is now an Open Access journal starting with volume 18 in 2009, and therefore there will be an inexpensive publication charge, which is dependent on the number of pages, in addition to the charge for color figures. This will allow work to be disseminated to a wider audience and also entitle the corresponding author to a free PDF, as well as prepublication of an unedited version of the manuscript.