The Cerebral Cortex

The Subcortical-Allocortical- Neocortical continuum for the Emergence and Morphological Heterogeneity of Pyramidal Neurons in the Human Brain

“…It is a cytoarchitectonic and functional specialization of the neocortex with participation in emotion, interoceptive and visceral modulation, attention, cognition, and complex perceptions as self-awareness ( Allman et al, 2001 ; Butti et al, 2013 ; Cauda et al, 2014 ; Correa-Júnior et al, 2020 and references therein). Likewise, the lateral parietal lobe adjacent to allocortical structures represents an evolved neocortical structure with primary, associative, and multimodal distributed functions ( Nieuwenhuys et al, 1988 ; Miller and Vogt, 1995 ; DeFelipe, 2011 ; Pandya et al, 2015 ; Kolb and Whishaw, 2015 ).…”

“… Ramón y Cajal (1894b) described cortical pyramidal neurons (or “psychic cells”) as “progressively larger and more complex in ascending the animal scale… to assume that at least part of its increased functional role is a result of increased morphological complexity… In descending the vertebrate ladder, the shape of the psychic cell becomes simpler, with its length and volume decreasing in parallel… differences are in microscopic form and the relative volume of particular components used in (brain) construction.” In humans, pyramidal neurons are found in forebrain structures ( Ramón y Cajal, 1894b , Ramón y Cajal, 1909–1911 ), but not in the striatum, the cerebellum, the brainstem, or in the spinal cord ( Spruston, 2008 ). These cells develop in the “anatomic limbic system” or “greater limbic lobe” ( Miller and Vogt, 1995 ; Wyss and van Groen, 1995 ; Gloor, 1997 ; Heimer et al, 2008 ) and are found in the heterogeneous allocortex and neocortex layers (i.e., except in cortical layer I, from layers II to VI and their subdivisions; Miller and Vogt, 1995 ; Andersen et al, 2007 ; DeFelipe, 2011 ), accounting for approximately 70–85% of all cells in the cerebral gray matter ( Nieuwenhuys, 1994 ; DeFelipe, 2011 ; Kolb and Whishaw, 2015 ).…”

“…In humans, pyramidal neurons are found in forebrain structures (Ramón y Cajal, 1894b, Ramón y Cajal, 1909-1911, but not in the striatum, the cerebellum, the brainstem, or in the spinal cord (Spruston, 2008). These cells develop in the "anatomic limbic system" or "greater limbic lobe" (Miller and Vogt, 1995;Wyss and van Groen, 1995;Gloor, 1997;Heimer et al, 2008) and are found in the heterogeneous allocortex and neocortex layers (i.e., except in cortical layer I, from layers II to VI and their subdivisions; Miller and Vogt, 1995;Andersen et al, 2007;DeFelipe, 2011), accounting for approximately 70-85% of all cells in the cerebral gray matter (Nieuwenhuys, 1994;DeFelipe, 2011;Kolb and Whishaw, 2015).…”