Neuronal cell transplantation for Parkinson's and Huntington's diseases.

The brain constitutes a privileged transplantation site. Under appropriate conditions neuronal tissues can survive transplantation into the damaged brain, integrate with the host, and alleviate functional impairments associated with neurological disease.The experimental techniques have been developed to the point of clinical application with demonstrable benefit in Parkinson's disease, and similar applications in Huntington's disease appear to be imminent. Nevertheless, present techniques require use of embryonic/fetal tissues which will limit the availability of donors for the foreseeable future.There is an active search for alternative sources of tissue that are equally effective but more readily available, including engineered cells, expanded stem/precursor cells, and xenografts. Transplantation of neuronal cells Transplantation of neural tissues (comprising both neurones and glial cells) offers considerable promise for providing radically new methods of treating a wide range of presently intractable neurodegenerative conditions of the central nervous system (CNS). The furthest progress has so far been achieved in Parkinson's disease (PD). However, the initial clinical trials are also now underway for pain and Huntington's disease (HD), with longer-term prospects of applications to motor neurones disease, epilepsy, multiple sclerosis and Alzheimer's disease all under active development. PD and HD are the two neurodegenerative diseases in which structural repair of neuronal circuits in the brain by cellular grafts is most advanced, and these will, therefore, provide the focus of Correspondence to , Dr Stephen B Dunne* the Present review. MRC Cambridge Centre The techniques of transplantati on in the CNS are not new, with the