Grindahvalur fleiri heilakyknur enn menniskja
Granskari á Umhvørvisstovuni hevur í sambandi við MSc serritgerð í lívfrøði greinað talið av heilakyknum í hvalaheilanum. Nú eru kanningarúrslitini útgivin í altjóða tíðarriti.
Í mai 2013 vardi Heidi S. Mortensen, ið arbeiðir sum málsviðgeri á Umhvørvisstovuni, sína MSc serritgerð í lívfrøði á Fróðskaparsetri Føroya.
Kanningin vísti m.a., at grindahvalur hevur í miðal 38 milliardir heilakyknur, og er hetta hægri enn hjá nøkrum øðrum súgdjóri, ið áður er kannað, íroknað menniskja, ið hava í miðal 20 milliardir heilakyknur.
Tað, at grindahvalur hevur næstan dupult so nógvar heilakyknur, samanborið við menniskja, er sera áhugavert, tí hildið hevur altíð verið, at menniskja hevur flest heilakyknur.
Í greinini verður tað m.a. viðgjørt hvønn týdning tað kann hava, at hava so nógvar heilakyknur.
Heidi hevur greinað talið av heilakyknum við einum kanningarhátti, ið nevninst stereologi. Kanningin bleiv gjørd í samstarvi við heilagranskarar á Bispebjerg Sjúkrahúsi og við granskingardeildina á Umhvørvisstovuni.
Greinin, ið kallast “Quantitative relationships in Delphinid neocortex” er útgivin í tíðarritinum Frontiers in Neuroanatomy, og kann lesast her
Enskur samandráttur
Possessing large brains and complex behavioural patterns, cetaceans are believed to be highly intelligent. Their brains, which are the largest in the Animal Kingdom and have enormous gyrification compared with terrestrial mammals, have long been of scientific interest. Few studies, however, report total number of brain cells in cetaceans, and even fewer have used unbiased counting methods. In this study, using stereological methods, we estimated the total number of cells in the long-finned pilot whale (Globicephala melas) brain. For the first time, we show that a species of dolphin has more neocortical neurons than in any mammal studied to date including humans. These cell numbers are compared across various mammals with different brain sizes, and the function of possessing many neurons is discussed. We found that the long-finned pilot whale neocortex has approximately 37.2 × 109 neurons, which is almost twice as many as humans, and 127 × 109 glial cells. Thus, the absolute number of neurons in the human neocortex is not correlated with the superior cognitive abilities of humans (at least compared to cetaceans) as has previously been hypothesized. However, as neuron density in long-finned pilot whales is lower than that in humans, their higher cell number appears to be due to their larger brain. Accordingly, our findings make an important contribution to the ongoing debate over quantitative relationships in the mammalian brain.

Vilt tú vita meira um kanningina, kanst tú seta teg í samband við Heidi S. Mortensen, tlf. 234342, HeidiM@us.fo
