Neuronal development in embryonic brain tissue derived from schizophrenic women and grafted to animal hosts

The distribution of schizophrenia in families supports the hypothesis of heritable risk factors in schizophrenia, but there is as yet no identification of an inherited neurobiological defect. Human embryonic brain tissue fragments, derived from first trimester abortions, can be transplanted into rat hosts, where they continue neuronal development and are accessible for neurobiological investigation. Hippocampal transplants derived from three schizophrenic women and a larger series of normal women have been studied. If there are heritable neuronal defects associated with schizophrenia, a proportion of the transplants from schizophrenic women would be expected to carry these defects. The transplants from the first two schizophrenic women showed profound abnormalities in survival and growth, compared to the series of transplants from normal women. The transplants from the third schizophrenic woman showed normal growth and development, as well as typical histological and electrophysiological features. The data must be regarded as preliminary, because of the small number of subjects that have been studied. However, they are consistent with the transmission of a defect in neuronal development to some of the offspring of schizophrenic women, a possibility consistent with other studies of the pathogenesis of schizophrenia. The mechanism of the defect in development remains to be identified.