The Neocortex of Indian River Dolphins (Genus Platanista): Comparative, Qualitative and Quantitative Analysis
We investigated the morphology of four primary neocortical projection areas (somatomotor, somatosensory, auditory, visual) qualitatively and quantitatively in the Indian river dolphins (Platanista gangetica gangetica, P. gangetica minor) with histological and stereological methods. For comparison, w...
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Online Access: | http://dx.doi.org/10.1159/000448274 https://www.karger.com/Article/Pdf/448274 |
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crskarger:10.1159/000448274 2024-06-09T07:49:56+00:00 The Neocortex of Indian River Dolphins (Genus Platanista): Comparative, Qualitative and Quantitative Analysis Knopf, Julian P. Hof, Patrick R. Oelschläger, Helmut H.A. 2016 http://dx.doi.org/10.1159/000448274 https://www.karger.com/Article/Pdf/448274 en eng S. Karger AG https://www.karger.com/Services/SiteLicenses https://www.karger.com/Services/SiteLicenses Brain, Behavior and Evolution volume 88, issue 2, page 93-110 ISSN 0006-8977 1421-9743 journal-article 2016 crskarger https://doi.org/10.1159/000448274 2024-05-15T13:31:00Z We investigated the morphology of four primary neocortical projection areas (somatomotor, somatosensory, auditory, visual) qualitatively and quantitatively in the Indian river dolphins (Platanista gangetica gangetica, P. gangetica minor) with histological and stereological methods. For comparison, we included brains of other toothed whale species. Design-based stereology was applied to the primary neocortical areas (M1, S1, A1, V1) of the Indian river dolphins and compared to those of the bottlenose dolphin with respect to layers III and V. These neocortical fields were identified using existing electrophysiological and morphological data from marine dolphins as to their topography and histological structure, including the characteristics of the neuron populations concerned. In contrast to other toothed whales, the visual area (V1) of the ‘blind' river dolphins seems to be rather small. M1 is displaced laterally and the auditory area (A1) is larger than in marine species with respect to total brain size. The layering is similar in the cortices of all the toothed whale brains investigated; a layer IV could not be identified. Cell density in layer III is always higher than in layer V. The maximal neuron density in P. gangetica gangetica is found in layer III of A1, followed by layers III in V1, S1, and M1. The cell density in layer V is at a similar level in all primary areas. There are, however, some differences in neuron density between the two subspecies of Indian river dolphins. Taken as a whole, it appears that the neocortex of platanistids exhibits a considerable expansion of the auditory field. Even more than other toothed whales, they seem to depend on their biosonar abilities for navigation, hunting, and communication in their riverine habitat. Article in Journal/Newspaper toothed whale toothed whales Karger Indian Brain, Behavior and Evolution 88 2 93 110 |
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English |
description |
We investigated the morphology of four primary neocortical projection areas (somatomotor, somatosensory, auditory, visual) qualitatively and quantitatively in the Indian river dolphins (Platanista gangetica gangetica, P. gangetica minor) with histological and stereological methods. For comparison, we included brains of other toothed whale species. Design-based stereology was applied to the primary neocortical areas (M1, S1, A1, V1) of the Indian river dolphins and compared to those of the bottlenose dolphin with respect to layers III and V. These neocortical fields were identified using existing electrophysiological and morphological data from marine dolphins as to their topography and histological structure, including the characteristics of the neuron populations concerned. In contrast to other toothed whales, the visual area (V1) of the ‘blind' river dolphins seems to be rather small. M1 is displaced laterally and the auditory area (A1) is larger than in marine species with respect to total brain size. The layering is similar in the cortices of all the toothed whale brains investigated; a layer IV could not be identified. Cell density in layer III is always higher than in layer V. The maximal neuron density in P. gangetica gangetica is found in layer III of A1, followed by layers III in V1, S1, and M1. The cell density in layer V is at a similar level in all primary areas. There are, however, some differences in neuron density between the two subspecies of Indian river dolphins. Taken as a whole, it appears that the neocortex of platanistids exhibits a considerable expansion of the auditory field. Even more than other toothed whales, they seem to depend on their biosonar abilities for navigation, hunting, and communication in their riverine habitat. |
format |
Article in Journal/Newspaper |
author |
Knopf, Julian P. Hof, Patrick R. Oelschläger, Helmut H.A. |
spellingShingle |
Knopf, Julian P. Hof, Patrick R. Oelschläger, Helmut H.A. The Neocortex of Indian River Dolphins (Genus Platanista): Comparative, Qualitative and Quantitative Analysis |
author_facet |
Knopf, Julian P. Hof, Patrick R. Oelschläger, Helmut H.A. |
author_sort |
Knopf, Julian P. |
title |
The Neocortex of Indian River Dolphins (Genus Platanista): Comparative, Qualitative and Quantitative Analysis |
title_short |
The Neocortex of Indian River Dolphins (Genus Platanista): Comparative, Qualitative and Quantitative Analysis |
title_full |
The Neocortex of Indian River Dolphins (Genus Platanista): Comparative, Qualitative and Quantitative Analysis |
title_fullStr |
The Neocortex of Indian River Dolphins (Genus Platanista): Comparative, Qualitative and Quantitative Analysis |
title_full_unstemmed |
The Neocortex of Indian River Dolphins (Genus Platanista): Comparative, Qualitative and Quantitative Analysis |
title_sort |
neocortex of indian river dolphins (genus platanista): comparative, qualitative and quantitative analysis |
publisher |
S. Karger AG |
publishDate |
2016 |
url |
http://dx.doi.org/10.1159/000448274 https://www.karger.com/Article/Pdf/448274 |
geographic |
Indian |
geographic_facet |
Indian |
genre |
toothed whale toothed whales |
genre_facet |
toothed whale toothed whales |
op_source |
Brain, Behavior and Evolution volume 88, issue 2, page 93-110 ISSN 0006-8977 1421-9743 |
op_rights |
https://www.karger.com/Services/SiteLicenses https://www.karger.com/Services/SiteLicenses |
op_doi |
https://doi.org/10.1159/000448274 |
container_title |
Brain, Behavior and Evolution |
container_volume |
88 |
container_issue |
2 |
container_start_page |
93 |
op_container_end_page |
110 |
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1801382886694191104 |