The development of intracerebral cell-suspension implants is influenced by the grafting medium

The effect of preparing and grafting embryonic striatal and nigral tissue in four different media was evaluated in vitro and in vivo. The proportion of TH-positive and DARPP-32-positive neurons was determined after 2 days in vitro in standard culture medium following preparation in the different media. The effects were more marked for striatal neurons where DARPP-32 expression in tissue prepared in HBSS was poor compared to other media. TH expression was unaffected by the preparation medium. Striatal grafts derived from tissue prepared and grafted in HBSS were smaller, with fewer DARPP-32 cells, compared to other media. Survival of grafts in combined HBSS and DMEM was very poor. Graft volume and TH cell content was enhanced in tissue prepared in DMEM. These results suggest that preparation protocols optimized for one type of embryonic neuronal population do not necessarily transfer to other neuronal populations.