[The effect of immune suppression on the take and development of the human neocortex transplanted into the spinal cord of the adult rat].

The reaction of rejection takes place in most cases of xeno-transplantations. It can be suppressed by hydrocortisone which inhibits processes of cell immunity. As a result the take of transplants is observed in 100% of cases. Processes of proliferation and differentiation of their cell elements are delayed. Little differentiated cells capable of mitotic division were noted to group into rosettes which might result from trauma of embryonic nervous tissues during taking the material or a reaction to the action of the environment. The injury of the spinal cord is followed by the formation of a scar deforming the surrounding structures which is formed not only by the glial but also by the connective tissue cells of spinal membranes. Against the background of immunosuppression a small soft scar is formed between the transplant and the host spinal cord consisting mainly of fibrous astrocytes.