The organization of the connections between the cortex and the claustrum in the monkey.

The distribution of labelled cells and of extracellular granules in the claustrum has been studied after injections of horseradish peroxidase in several areas of the neocortex. The frontal and parietal lobes are related to the anterior and posterior halves respectively of the claustrum, and the occipital and temporal cortex to the posterior and inferior margins. Parts of the claustrum related to areas of the cortex in the frontal lobe overlap considerably in the antero-posterior dimension with parts related to widely separated but interconnected areas of the parieto-temporal cortex. Areas of cortex within one lobe which are interconnected are related to parts of the claustrum which overlap in the dorsoventral dimension.