Von Economo Neurons in the Anterior Insula of the Macaque Monkey

• Published in: Neuron (Cambridge, Mass.) Vol. 74; no. 3; pp. 482 - 489
• Main Authors: Evrard, Henry C., Forro, Thomas, Logothetis, Nikos K.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 10-05-2012; Elsevier Limited
• Subjects: Analysis of Variance; Animals; Brain; Cell Count; Cerebral Cortex - cytology; Cognition; Cortex (insular); Female; Humans; Macaca; Macaca fascicularis; Macaca mulatta; Male; Mental disorders; Monkeys & apes; Nerve Tissue Proteins - metabolism; Neurons; Neurons - physiology; Neurons - ultrastructure; Phylogeny; Primates; Receptor, Serotonin, 5-HT2B - metabolism; Silver Staining - methods; Social interactions; Stereotaxic Techniques
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/j.neuron.2012.03.003

The anterior insular cortex (AIC) and its unique spindle-shaped von Economo neuron (VEN) emerged within the last decade as having a potentially major role in self-awareness and social cognition in humans. Invasive examination of the VEN has been precluded so far by the assumption that this neuron occurs among primates exclusively in humans and great apes. Here, we demonstrate the presence of the VEN in the agranular anterior insula of the macaque monkey. The morphology, size, laminar distribution, and proportional distribution of the monkey VEN suggest that it is at least a primal anatomical homolog of the human VEN. This finding sheds new light on the phylogeny of the VEN and AIC. Most importantly, it offers new and much-needed opportunities to investigate the primal connections and physiology of a neuron that could be crucial for human self-awareness, social cognition, and related neuropsychiatric disorders.
► Von Economo neurons (VENs) occur in the anterior insula in macaques ► Concentrated VEN populations in primates are not an exclusivity of hominids ► The VEN's phylogeny needs to be reexamined ► Much-needed examinations of the VEN's connections and physiology are now possible
The von Economo neuron (VEN) in the anterior insula has been proposed to play a role in self-awareness and social cognition but had been presumed to occur only in humans and great apes. Evrard et al. demonstrate anatomical evidence for a macaque VEN, opening the way for functional tests of its role in cognition.