Epilepsy is a disease where a lack of inhibition in certain areas of the brain lead to seizures. It has been proposed that the implantation of embryonic inhibitory nerve cells could be used as a means for treating epilepsy. This may prove to be difficult because of the lack of a specific site to place the cells. Furthermore, most animal models of neural cell implantation for controlling epilepsy occurred before the onset of epilepsy, while in humans we would want a solution that could deal with ongoing epilepsy. Nevertheless, inhibitory neurons have been implanted in patients who were going to have nervous tissue removed anyway (Bjorklund and Lindvall 2000).
Recent research in depression has suggested that one of the causes of depression may be a suppression of neuronal growth and plasticity, including the normal development of stem cells in the brain. It has also been suggested that one of the ways that anti-depressants work is by promoting neural growth. Though no treatment of depression through stem cell graft has been proposed, treatments that increase the likelihood of innate neurogenesis could be an effective treatment for depression (Czeh et al.).