Laminar distribution of cortical projection neurons to the pulvinar: A comparative study in cats and mice
| Autor: | Christian Casanova, Bruno Oliveira Ferreira de Souza, Eve-Marie Frigon, Denis Boire, Robert Tremblay-Laliberté |
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| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Male media_common.quotation_subject Thalamus Pulvinar nuclei Biology Pulvinar 03 medical and health sciences Mice 0302 clinical medicine Projection (mathematics) Species Specificity medicine Distribution (pharmacology) Contrast (vision) Animals Visual Pathways media_common Cerebral Cortex CATS General Neuroscience Laminar flow Mice Inbred C57BL 030104 developmental biology Visual cortex medicine.anatomical_structure nervous system Cats Female Neuroscience 030217 neurology & neurosurgery |
| Zdroj: | The Journal of comparative neurologyREFERENCES. 529(8) |
| ISSN: | 1096-9861 |
| Popis: | The cortical processing of visual information is thought to follow a hierarchical framework. This framework of connections between visual areas is based on the laminar patterns of direct feedforward and feedback cortico-cortical projections. However, this view ignores the cortico-thalamo-cortical projections to the pulvinar nucleus in the thalamus, which provides an alternative transthalamic information transfer between cortical areas. It was proposed that corticothalamic (CT) pathways follow a similar hierarchical pattern as cortico-cortical connections. Two main types of CT projections have been recognized: drivers and modulators. Drivers originate mainly in Layer 5 whereas modulators are from Layer 6. Little is known about the laminar distribution of these projections to the pulvinar across visual cortical areas. Here, we analyzed the distribution of CT neurons projecting to the lateral posterior (LP) thalamus in two species: cats and mice. Injections of the retrograde tracer fragment B of cholera toxin (CTb) were performed in the LP. The morphology and cortical laminar distribution of CTb-labeled neurons was assessed. In cats, neurons were mostly found in Layer 6 except in Area 17, where they were mostly in Layer 5. In contrast, CT neurons in mice were mostly located in Layer 6 across all areas. Thus, our results demonstrate that CT projections in mice do not follow the same organization as cats suggesting that the transthalamic pathways play distinct roles in these species. |
| Databáze: | OpenAIRE |
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