Theories of basal forebrain organization and the "emotional motor system".

Publisher Summary This chapter focuses on the neuroanatomy of the heterogenous structures that comprise the basal forebrain, insofar as this territory, together with its most closely associated cortical areas, is likely to provide important projections activating emotionally related motor areas of the brainstem. Special consideration is given to the ventral striatopallidal system and the extended amygdala and areas of transition between these two systems. Many of the structures in the basal forebrain have been included within the various conceptualizations of the limbic system, and the majority of behavioral observations following the early formulations of this concept by Papez and MacLean have generally reinforced the notion that the basal forebrain is systematically involved in the experience and expression of emotions. To some extent, the description of a “descending limbic motor control system” can face difficulties similar to the definition of the “limbic system” at large. The chapter also summarizes the multiple output channels from the basal forebrain to the motor areas of the brainstem.