Afferent and efferent connections between the claustrum and parietal association cortex in cat: a horseradish peroxidase and autoradiographic study.

Combined injections of [3H]proline and horseradish peroxidase (HRP) were made into acoustically responsive cortical association areas on the middle suprasylvian gyrus (MSA) and anterior lateral gyrus (ALA) in the cat. Sources and terminations of cortical axons were located within the claustrum. There are three findings: (1) MSA and ALA project to and receive fibers from restricted areas of the dorsal claustrum. The locations of the projection fields within the claustrum are different for the two cortical areas; (2) the afferent and efferent projection fields in the claustrum are coextensive suggesting a reciprocal claustral-cortical relationship and (3) the projections are bilateral with the ipsilateral projection predominating.