Pretectal connections to the claustrum: an HRP retrograde transport study in cats

In 28 cats after injections of HRP solution (0.20-0.50 mikrol) to the claustrum from the lateral side or from above, large numbers of HRP labeled cells were found in the anterior pretectal nuclei. This concerned the anterior compact nucleus more than the anterior reticular. This type of labeling was not observed after injections of HRP to the cerebral cortex and striatum. The results speak in favor of a great a number of pretecto-claustral axons connecting the anterior pretectal neurons with the claustrum.