THE physical process of cell suspension preparation from embryonic ventral mesencephala (VM) may be responsible for the low numbers of dopaminergic (DA) neurons that survive following neural transplantation orin vitroculture. In particular, the disruption of cell to extra-cellular matrix attachment may result in cell death through deactivation of a cAMP-dependent protein kinase involved in cell survival signalling. In an attempt to reduce this death, dibutyryl cAMP was included in all solutions from explant collection to final dissociation. Pretreatment with 700μM dibutyryl cAMP resulted in 90% survival of the DA neurons originally plated, compared with only 40% in the untreated cultures, after 5 daysin vitro. Treatment of VM explants in this manner may result in major improvements in neural transplantation as a technique for the treatment of Parkinson's disease.