Cortical Evolution: Introduction to the Reptilian Cortex

  title={Cortical Evolution: Introduction to the Reptilian Cortex},
  author={Gilles Laurent and Julien Fournier and Mike Hemberger and Christian R. M{\"u}ller and Robert Konrad Naumann and Jan Ondracek and Lorenz Pammer and Sam Reiter and Mark Shein-Idelson and Maria Antonietta Tosches and Tracy M Yamawaki},
Some 320 million years ago (MYA), the evolution of a protective membrane surrounding the embryo, the amnion, enabled vertebrates to develop outside water and thus invade new terrestrial niches. These amniotes were the ancestors of today’s mammals and sauropsids (reptiles and birds). Present-day reptiles are a diverse group of more than 10,000 species that comprise the sphenodon, lizards, snakes, turtles and crocodilians. Although turtles were once thought to be the most “primitive” among the… Expand
On the evolutionary origin of the vertebrate cortex
The overall results of the four studies demonstrated an unforeseen level of conservation of the basic microcircuitry, cytoarchitecture, cell-types, efferent connectivity and sensorimotor organisation of the lamprey LPal/cortex providing compelling evidence for common ancestry with the mammalian neocortex. Expand
Variations of telencephalic development that paved the way for neocortical evolution
Highlights • To reveal how the neocortex emerged during evolution we need to understand the evolution of the development of the pallium.• The developmental trajectories of cortical cells areExpand


The Cerebral Cortex of Reptiles
It is only in reptiles and mammals that the telencephalic roof develops into extensive and multilayered cortices. Expand
The evolutionary origin of the mammalian isocortex: Towards an integrated developmental and functional approach
The isocortex may have originated partly as a consequence of an overall “dorsalizing” effect during pallial development, which was driven by selective pressures favoring the development of associative networks between the dorsal cortex, the olfactory cortex, and the hippocampus, which participated in spatial or episodic memory in the early mammals. Expand
The evolutionary origin of the mammalian isocortex: insights from molecular developmental biology
Developmental approach is inclined for the developmental approach, which prescribes non-homology between the isocortex and the dorsal ventricular ridge, and suggests a scenario for the origin of theIsocortex as an expansion of the reptilian dorsal cortex, which is consistent with current evidence. Expand
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The relatively sophisticated armamentarium of neurobiological tech­ niques available today allows us to establish more accurately the anatomy of the telencephalon; these data, data from the fossil record, and a more sophisticated view of vertebrate phylogeny allow us to propose and test new hypotheses regarding the evolution of the vertebrate telencesphalon. Expand
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Observations for turtles suggest that turtle cortex in particular and reptilian telencephalic cortex in general must differ functionally from mammalian isocortex with respect to those features associated with the laminar and columnar organization of isoc cortex. Expand
Morphology of geniculocortical axons in turtles of the genera Pseudemys and Chrysemys
Data indicate that the terminal zone of the dorsal lateral geniculate complex within the telencephalon of turtles is more extensive in the mediolateral direction than previously believed. Expand
Cell-type homologies and the origins of the neocortex
It is established that the layer 4 input and the layer 5 output cell types are conserved across the amniotes, but are organized into very different architectures, forming nuclei in birds, cortical areas in reptiles, and cortical layers in mammals. Expand
Dendritic properties of turtle pyramidal neurons.
It is concluded that spike backpropagation, dendritic Ca2+ channels, and synaptically activated Ca 2+ release are primitive and conserved features of cortical pyramidal cells, and therefore likely fundamental to cortical function. Expand
The thalamocortical projection in Pseudemys turtles: A quantitative electron microscopic study
It is suggested that the stellate cells in the thalamic input zone are inhibitory and that eachThalamic volley not only excites efferent pyramidal cells but is also a powerful activator of inhibitory interneurons. Expand
The Microcircuit Concept Applied to Cortical Evolution: from Three-Layer to Six-Layer Cortex
The microcircuits concept is used to focus first on the principles of microcircuit organization of three-layer cortex in the olfactory cortex, hippocampus, and turtle general cortex, and compare it with six-layer neocortex to help understand the expanded functional capabilities elaborated by the evolution of the neocortex. Expand