A method for recording single unit activity from the brains of foetal pigs in utero

A technique is described for recording single unit activity from foetal miniature pigs in utero. The method involved anaesthetizing the sows with halothane and exteriorizing a sufficient length of the uterus to contain a single foetus. Both foetus and uterus were placed in a stereotaxic frame which was held independent of the mothers' support. Preliminary analysis of recordings obtained from spontaneously firing single nerve cells in the post-central cerebral cortex indicate that the patterns of spike activity in prenatal pigs are very similar to those observed in prepubertal animals.