Transplanted dopamine neurons derived from primate ES cells preferentially innervate DARPP-32 striatal progenitors within the graft

The correct identity and functional capacity of transplanted dopamine (DA) neurons derived in vitro from embryonic stem (ES) cells is a critical factor for the development of an ES cell‐based replacement therapy for Parkinson's disease. We transplanted primate Cyno‐1 ES cells differentiated in vitro for 4 (progenitor ES cells) or 6 (differentiated ES cells) weeks, or control fetal primate cells into the striatum of hemi‐parkinsonian rats. Partial behavioral recovery in amphetamine‐induced rotation was correlated with the number of ES‐derived tyrosine hydroxylase‐positive (TH +) neurons in the grafts (r = 0.5, P 90%) in grafts from differentiated ES cells than in grafts derived from progenitor cells (