Unraveling the Seat of Consciousness: Anatomical Redefinition and Molecular Characterization of the Claustrum

Abstract

The claustrum is a telencephalic grey matter nucleus of unclear structure and function, although it has been recently proposed to be a generator of conscious percepts. Our studies redefine the structural boundaries and connections of the claustrum in the rat, as well as provide evidence for an equivalent redefinition of claustral anatomy in all therian mammal brains, including human. An analysis of cortical representations in the claustrum are also presented and the findings are considered in a functional context. Finally, G protein gamma-2 is identified as a novel and discrete neuroanatomical marker of the claustrum whose expression pattern is in register with the our anatomical definitions. The results of this work alter long-held tenets of claustral anatomy and allow for an assessment of claustral function through molecular lesioning techniques targeting G protein gamma-2.