Phase 1 of an in vitro neurotoxicological pre-validation trial

In the absence of a formal in vitro alternative model for neurotoxicity testing, the CellTox Centre, in collaboration with the University of Salford, FRAME and the EEC, has set up an initial pre-validation trial of a three-tiered scheme that was originally proposed in 1989. Using a cell battery of neuroblastomas and primary neural cultures (Tier I) and primary astrocytes (Tier III) an initial set of 20 chemicals (out of a reference set of 40 chemicals) has been assessed for neurotoxicity using a multiple end point assay system. The methods used were relatively simple, rapid and inexpensive, and the chemical end points were easily quantified. The results of the pre-validation trial have enabled us to revise the first tier of the proposed tiered system for full micro-validation.