hide
Free keywords:
-
Abstract:
The anterior insular (AIC) and anterior cingulate (ACC) cortices and their unique spindle-shaped von Economo neurons (VENs) emerged within the last decade as having a potentially major role in interoceptive, emotional and social awareness and cognition in humans. A role of the VENs in these fundamental phenomena is supported by their selective depletion in highly detrimental neuropsychiatric diseases characterized by a loss of self-conscious emotion and empathy and by a lack of appropriate behavioral response in emotionally-salient situations. The much-needed invasive examination of the VENs in the laboratory has been limited so far by the assumption that this neuron occurs among primates exclusively in humans and great apes. In a recent contribution, we demonstrated the presence of VENs in the agranular anterior insula and ACC in two species of macaque monkeys (rhesus and cynomolgus) typically used in the laboratory. VENs were also found in the same regions in a broad range of monkeys and in lesser apes. In the present contribution, we demonstrate that VENs in the macaque occur in an architectonically distinct area of the agranular anterior insula, namely ´Ia5´, and in several distinct areas in ACC and in the medial wall of the prefrontal cortex. This specific areal distribution of the VENs suggests that their developmental fate is bound to the overall plan of development and parcellation of the cerebral cortex in primates. It also offers a unique opportunity to examine the primal function and connections of the VENs on the basis of what is already known about these areas in the macaque monkey. Such examination could provide significantly new and valuable information on the possible role of the VENs in human self-awareness, social cognition and related neuropsychiatric disorders.