Pyramidal Cells in Prefrontal Cortex of Primates: Marked Differences in Neuronal Structure Among Species

The most ubiquitous neuron in the cerebral cortex, the pyramidal cell, is characterized by markedly different dendritic structure among different cortical areas. The complex pyramidal cell phenotype in granular prefrontal cortex (gPFC) of higher primates endows specific biophysical properties and patterns of connectivity, which differ from those in other cortical regions. However, within the gPFC, data have been sampled from only a select few cortical areas. The gPFC of species such as human and macaque monkey includes more than 10 cortical areas. It remains unknown as to what degree pyramidal cell structure may vary among these cortical areas. Here we undertook a survey of pyramidal cells in the dorsolateral, medial, and orbital gPFC of cercopithecid primates. We found marked heterogeneity in pyramidal cell structure within and between these regions. Moreover, trends for gradients in neuronal complexity varied among species. As the structure of neurons determines their computational abilities, memory storage capacity and connectivity, we propose that these specializations in the pyramidal cell phenotype are an important determinant of species-specific executive cortical functions in primates.Supported by grants from the National Health and Medical Research Council of Australia (Guy N. Elston), the McDonnell Foundation (Guy N. Elston), the Japanese Science and Technology Corporation (Guy N. Elston), Hear and Say Australia (Guy N. Elston), CIBERNED CB06/05/0066 (Javier DeFelipe), Fundación CIEN (Javier DeFelipe), and the Spanish Ministry of Education, Science and Innovation SAF2009-09394 (Javier DeFelipe), and the South African National Research Foundation (Paul R. Manger).Peer Reviewe