Mechanisms by which hyperbaric oxygen improves sequelae following brain injury are speculative. Hyperbaric oxygen upregulates growth factor receptor sites on human endothelium and can stimulate healing in hypoxic wounds. It is conceivable that hyperbaric oxygen exerts similar effects within damaged neuronal tissue but this information is lacking. Stem cells are present in the adult brain and there is speculation that hyperbaric oxygen may stimulate these stem cells to generate new neurons, but once again, this information is speculative.