Abstract
The current study used a range of standard and immunohistochemical neuroanatomical stains to investigate the architectural organization of the cerebral cortex of the sengis (elephant shrews). We were able to identify four distinct cortical morphotypes – a medial neocortical, a lateral neocortical, a cingulate and a piriform. While the architectural organization of the medial neocortical, lateral neocortical and piriform morphotypes were similar to that seen in many other mammals, the cingulate cortical morphotype displayed a lamination pattern unique to the order Macroscelidae order. The cingulate cortex of the sengis displayed a very wide layer 4 and a reduced and granular-looking layer 3. Despite this variation in the laminar architecture of the cingulate cortex, cortical minicolumns were present in all regions of the cerebral cortex. Interestingly, all regions of cortex displayed apical dendrites immunoreactive to uncoupling protein 2, a marker of thermogenesis. Thus, the sengis display a unique mixture of morphologies that are standard across mammals and unique to their order. This mixture indicates that the development of horizontal lamination patterns and vertical columnar organization may be distinctly controlled and not interdependent aspects of cortical development. The sengis may provide a unique animal model of cortical development that could unlock clues to the development of cortical architectural variation across mammalian species.
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Manger, P. et al. (2015). Unusual Cortical Lamination Patterns in the Sengis (Elephant Shrews) Do Not Appear to Influence the Presence of Cortical Minicolumns. In: Casanova, M., Opris, I. (eds) Recent Advances on the Modular Organization of the Cortex. Springer, Dordrecht. https://doi.org/10.1007/978-94-017-9900-3_6
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DOI: https://doi.org/10.1007/978-94-017-9900-3_6
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