The term limbic system denotes a composite substructure of forebrain that is variously defined on the basis of function and connectivity. For most authors it includes the cingulate gyrus, the parahippocampal gyrus, the hippocampal complex, the septal nuclei, the amygdala, the hypothalamus, the epithalamus, the anterior nuclear group of the thalamus and portions of the basal ganglia. For a review of differences in the definition of this term see Anthoney-1994. See also limbic lobe.