Selective brain cooling and its vascular basis in diving seals
Brain ( T brain ), intra-aorta ( T aorta ), latissimus dorsi muscle ( T m ) and rectal temperature ( T r ) were measured in harp ( Pagophilus groenlandicus ) and hooded ( Cystophora cristata ) seals during experimental dives in 4°C water. The median brain cooling was about 1°C during 15 min diving,...
Published in: | Journal of Experimental Biology |
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fthighwire:oai:open-archive.highwire.org:jexbio:213/15/2610 2023-05-15T15:59:54+02:00 Selective brain cooling and its vascular basis in diving seals Blix, Arnoldus Schytte Walløe, Lars Messelt, Edward B. Folkow, Lars P. 2010-08-01 00:00:00.0 text/html http://jeb.biologists.org/cgi/content/short/213/15/2610 https://doi.org/10.1242/jeb.040345 en eng Company of Biologists http://jeb.biologists.org/cgi/content/short/213/15/2610 http://dx.doi.org/10.1242/jeb.040345 Copyright (C) 2010, Company of Biologists Research Articles TEXT 2010 fthighwire https://doi.org/10.1242/jeb.040345 2015-02-28T21:02:19Z Brain ( T brain ), intra-aorta ( T aorta ), latissimus dorsi muscle ( T m ) and rectal temperature ( T r ) were measured in harp ( Pagophilus groenlandicus ) and hooded ( Cystophora cristata ) seals during experimental dives in 4°C water. The median brain cooling was about 1°C during 15 min diving, but in some cases it was as much as 2.5°C. Cooling rates were slow for the first couple of minutes, but increased significantly after about 5 min of diving. The onset of cooling sometimes occurred before the start of the dive, confirming that the cooling is under cortical control, like the rest of the diving responses. T aorta also fell significantly, and was always lower than T brain , while T m was fairly stable during dives. Detailed studies of the vascular anatomy of front flippers revealed that brachial arterial blood can be routed either through flipper skin capillaries for nutritive purposes and return through sophisticated vascular heat exchangers to avoid heat loss to the environment, or, alternatively, through numerous arterio-venous shunts in the skin and return by way of large superficial veins, which then carry cold blood to the heart. In the latter situation the extent to which the brain is cooled is determined by the ratio of carotid to brachial arterial blood flow, and water temperature, and the cooling is selective in that only those organs that are circulated will be cooled. It is concluded that T brain is actively down-regulated during diving, sometimes by as much as 2.5°C, whereby cerebral oxygen requirements may be reduced by as much as 25% during extended dives. Text Cystophora cristata Pagophilus groenlandicus HighWire Press (Stanford University) Journal of Experimental Biology 213 15 2610 2616 |
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Research Articles |
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Research Articles Blix, Arnoldus Schytte Walløe, Lars Messelt, Edward B. Folkow, Lars P. Selective brain cooling and its vascular basis in diving seals |
topic_facet |
Research Articles |
description |
Brain ( T brain ), intra-aorta ( T aorta ), latissimus dorsi muscle ( T m ) and rectal temperature ( T r ) were measured in harp ( Pagophilus groenlandicus ) and hooded ( Cystophora cristata ) seals during experimental dives in 4°C water. The median brain cooling was about 1°C during 15 min diving, but in some cases it was as much as 2.5°C. Cooling rates were slow for the first couple of minutes, but increased significantly after about 5 min of diving. The onset of cooling sometimes occurred before the start of the dive, confirming that the cooling is under cortical control, like the rest of the diving responses. T aorta also fell significantly, and was always lower than T brain , while T m was fairly stable during dives. Detailed studies of the vascular anatomy of front flippers revealed that brachial arterial blood can be routed either through flipper skin capillaries for nutritive purposes and return through sophisticated vascular heat exchangers to avoid heat loss to the environment, or, alternatively, through numerous arterio-venous shunts in the skin and return by way of large superficial veins, which then carry cold blood to the heart. In the latter situation the extent to which the brain is cooled is determined by the ratio of carotid to brachial arterial blood flow, and water temperature, and the cooling is selective in that only those organs that are circulated will be cooled. It is concluded that T brain is actively down-regulated during diving, sometimes by as much as 2.5°C, whereby cerebral oxygen requirements may be reduced by as much as 25% during extended dives. |
format |
Text |
author |
Blix, Arnoldus Schytte Walløe, Lars Messelt, Edward B. Folkow, Lars P. |
author_facet |
Blix, Arnoldus Schytte Walløe, Lars Messelt, Edward B. Folkow, Lars P. |
author_sort |
Blix, Arnoldus Schytte |
title |
Selective brain cooling and its vascular basis in diving seals |
title_short |
Selective brain cooling and its vascular basis in diving seals |
title_full |
Selective brain cooling and its vascular basis in diving seals |
title_fullStr |
Selective brain cooling and its vascular basis in diving seals |
title_full_unstemmed |
Selective brain cooling and its vascular basis in diving seals |
title_sort |
selective brain cooling and its vascular basis in diving seals |
publisher |
Company of Biologists |
publishDate |
2010 |
url |
http://jeb.biologists.org/cgi/content/short/213/15/2610 https://doi.org/10.1242/jeb.040345 |
genre |
Cystophora cristata Pagophilus groenlandicus |
genre_facet |
Cystophora cristata Pagophilus groenlandicus |
op_relation |
http://jeb.biologists.org/cgi/content/short/213/15/2610 http://dx.doi.org/10.1242/jeb.040345 |
op_rights |
Copyright (C) 2010, Company of Biologists |
op_doi |
https://doi.org/10.1242/jeb.040345 |
container_title |
Journal of Experimental Biology |
container_volume |
213 |
container_issue |
15 |
container_start_page |
2610 |
op_container_end_page |
2616 |
_version_ |
1766395788980649984 |