Chapter 3 Qualitative and quantitative comparison of the prefrontal cortex in rat and in primates, including humans

Abstract

This chapter focuses on the qualitative and quantitative comparison of the prefrontal cortex (PFC) in rats and in primates, including humans. Comparing the different connectivity patterns and the relative PFC size in rats and primates, the evolution of the PFC is most probably a result of both an increase in cortical size and of the segregation and specialization of the cortical regions. The segregation and extension of the cortical ocular dominance columns after birth, which can coincide with the elimination of the neuronal structures that have become exuberant during development, is reviewed in the chapter. It also considers homology criteria in comparing the rat PFC with the primate PFC and the connections with the thalamus, corticocortical connections, and the connections with other subcortical nuclei. Only those cortical areas are included in the PFC for which the reciprocal connections with the mediodorsal nucleus are stronger than are the connections with other thalamic nuclei. When the criterion of heaviest reciprocal connections with MD is applied to the current data on thalamic connections, the cortical areas are regarded as PFC areas. The connectivity patterns of the rat and primate MDs are compared in the chapter. It also tabulates the current data on reciprocal cortical connections with the different parts of the mediodorsal nucleus in the rat and primate. It shows that the topographies of these cortical connections in the rat and primate are quite similar.