Claustral afferents to the rat's visual cortex

Horseradish peroxidase (HRP) was injected electrophoretically into the rat's primary visual cortex (V1), and three other retinotopically organized cortical areas, anterior medial visual area (AM), posterior medial visual area (PM) and anterior lateral area (AL). While the HRP injections into V1 labelled many neurons in the ipsilateral claustrum, the injections in any of the three other visual areas labelled very few claustral neurons.