RECIPROCAL AND TOPOGRAPHIC CONNECTIONS BETWEEN THE PIRIFORM AND PREFRONTAL CORTICES IN THE RAT - A TRACING STUDY USING THE B-SUBUNIT OF THECHOLERA-TOXIN

In the present study, the reciprocal connections between the piriform cortex and the prefrontal areas are described on the basis of experime nts using the anterograde and the retrograde transport of the cholera toxin B subunit (CTb). Following CTb injections placed in the anterior part of the piriform cortex, retrogradely labeled cells and anterogra dely labeled fibers were mainly found in the ventrolateral and lateral orbital areas as well as in the anterior part of the agranular insula r cortex. Following injections placed in the posterior part of the pir iform cortex, the CTb labeling was primarily observed in the infralimb ic area and the posterior part of the agranular insular cortex. Thus, we described a topographical organization of the direct reciprocal con nections between the anterior and the posterior parts of the piriform cortex parts and some prefrontal areas. This could support st differen tial modulation of the olfactory processing along the rostrocaudal dim ension of the piriform cortex. Copyright (C) 1996 Elsevier Science Inc .