Projections from the pretectothalamic border area to the somatosensory part of the claustrum: an autoradiographic study.

Injections of tritiated amino acid into the pretectothalamic border area of cats resulted in the appearance of numerous silver grains in the ipsilateral claustrum. The accumulation of grains was especially abundant in the dorsomedial area of the central part of the claustrum. These results indicate the presence of substantial projection from the pretectothalamic border area to the claustrum. It may be assumed that these projections belong to the somatosensory system, since they connect mainly di(mes)encephalic nuclei, receiving largely the somatosensory input, with the somatosensory part of the claustrum.