Von Economo neurons (VENs) are a distinct and intriguing type of brain cell. These specialized neurons represent a unique aspect of brain architecture, and their precise role in brain function is a subject of ongoing scientific inquiry. Researchers investigate how VENs contribute to complex behaviors and their potential involvement in various neurological conditions.
Unveiling Von Economo Neurons
Von Economo neurons are characterized by their distinctive morphology: a large, spindle-shaped cell body that tapers into a single apical axon. This unique bipolar shape sets them apart from many other cortical neurons. Their elongated cell body has also led to descriptions as “stick,” “rod,” or “corkscrew” cells.
These specialized neurons are found primarily in two restricted brain regions: the anterior cingulate cortex (ACC) and the frontoinsular cortex (FI). Both areas are part of the salience network, a brain system involved in detecting and responding to significant internal and external stimuli. While first noted by Santiago Ramón y Cajal in 1899, VENs were formally described and named in 1925 by Austrian psychiatrist and neurologist Constantin von Economo. He initially considered their peculiar morphology to be a pathological alteration but later recognized them as a unique neuron subtype.
Their Role in Social Cognition and Evolution
VENs are considered evolutionarily significant due to their presence mainly in large-brained, highly social mammals. They are found in great apes, including humans, chimpanzees, bonobos, gorillas, and orangutans. Beyond primates, VENs have also been identified in cetaceans (whales and dolphins) and African and Asian elephants. This distribution across distantly related species suggests convergent evolution, where similar traits evolve independently in different lineages, potentially as an adaptation to accommodate increasing brain size and complex social behaviors.
The proposed functions of VENs center around their roles in rapid intuitive social judgments and the processing of complex emotions. Their unique structure may facilitate fast and efficient communication within social processing networks. This rapid communication is particularly beneficial for quick assessments of social situations, contributing to functions like empathy and self-awareness. The presence of VENs in areas associated with the “social brain” suggests their involvement in coordinating emotional and interoceptive signals, providing swift connections between widely separated brain regions.
Implications for Neurological Disorders
Von Economo neurons are implicated in various neurological and psychiatric conditions, suggesting their vulnerability to disease processes. A prominent example is Frontotemporal Dementia (FTD), particularly its behavioral variant (bvFTD), where significant loss or damage to VENs is a recognized feature. The degeneration of these neurons in FTD contributes to the characteristic changes in social behavior, emotional regulation, and self-control observed in affected individuals. Research indicates that VENs may be more susceptible to the neurodegenerative processes seen in FTD compared to other neuron types.
VEN dysfunction has also been explored in other neuropsychiatric disorders, including Autism Spectrum Disorder (ASD) and schizophrenia. Abnormalities in VEN numbers or morphology are observed in these conditions. For instance, a reduced density of VENs has been observed in the anterior cingulate cortex in schizophrenia. These findings suggest that alterations in VENs might contribute to the social and cognitive challenges experienced by individuals with ASD and schizophrenia.