THE CORTICO-RELATED ZONES OF THE RABBIT CLAUSTRUM - STUDY OF THE CLAUSTROCORTICAL CONNECTIONS BASED ON THE RETROGRADE AXONAL-TRANSPORT OF FLUORESCENT TRACERS

The claustrocortical connections in the rabbit were assessed for the f irst time by the method of axonal retrograde transport of two fluoresc ent tracers (Fast Blue and Diamidino Yellow). The material consisted o f 23 adult New Zealand rabbits. Projection zones of spindle-like form, connected with the precentral, postcentral, temporal and occipital co rtices have been delineated. They are organized topographically both i n the anteroposterior and ventrodorsal direction. The precentral (moto r) projection zone is localized in the anterodorsal part of the claust rum. It may be divided into two separate parts that project to the med ial and lateral part of the precentral cortex. The large postcentral ( somatosensory) zone occupies mainly the central part, whereas the temp oral (auditory) and occipital (visual) zones are situated in the poste roventral part of the claustrum. The overlap of various claustral proj ection zones is differentiated, the largest being that of the somatose nsory zones. In comparison to the results of study of claustral projec tion zones performed on other species, presumably on the rat and cat, its seems plausible to conclude that the extension of claustral projec tion zones and degree of their overlap in the rabbit represent an inte rmediate character. (C) 1998 Elsevier Science B.V.