INTRAUTERINE SILASTIC EMBEDDING OF MAMMALIAN FETUSES FOR SURGICAL IMMOBILIZATION

Since the beginning of this century intra uterine operations were perf ormed upon foetal mammals in order to study regeneration and developme nt. Although methods became more refined, manipulation of the animals remained difficult and stereotaxic methods were never developed. In th is study we describe a method to improve intra-uterine manipulation an d stereotaxis by replacing amniotic fluid with silicone rubber, which immobilises the foetus. Survival times up to 24 hours were achieved, s ufficient for neuronal tracing or for electrophysiological recording. All experiments were performed at embryonic day 18 (E18).