Some properties of the cat's isolated cerebral cortex

This paper is concerned with the properties of the cat's cerebral cortex, treated as an isolated organ. The experiments have all been performed upon a layer composed of cortical grey matter with some of the underlying cortico-cortical fibres; this slab of tissue has been isolated from all connexion with either the central nervous system or the adjacent cortex, its blood supply being the only connexion with the rest of the animal. An attempt to determine the properties of isolated cortical tissue scarcely needs justification. Although the electrical activity seen in a preparation of this sort is, no doubt, far removed from the behaviou-r of the intact cortex, the properties of the isolated cortex, despite its diverse cell types and unknown intercellular connedions seem, in the present state of knowledge, to make an easier subject for research than does the behaviour of the intact brain. A short summary of the preliminary work with the preparation has already been reported (Burns, 1949). In reporting experiments carried out with a preparation of one type, it is easy to give the impression that the results obtained are applicable to all normal cortical tissue. I think it is important, therefore, to stress at the outset, the extremely limited nature of these experiments, all of which have been made on one small area of the cat's brain, using only one anaesthetic.