BighistoryやSapience的考察からヒト、科学、学習、言語、芸術、心、脳にゃどあれこれ思考する"更新型"メモノートです📖 よって、グルーミング用の旬な時事ネタはないです…か?


又吉直樹のヘウレーカ! - NHK 出演研究者である古屋晋一氏のtwiterを見ていたら面白い記事に出あったのでその翻訳もどきで紹介します

What Scientists Saw When They Put a Crocodile in an MRI Scanner and Played Classical Music

The lives of some scientists are anything but boring. In a world first, researchers placed a Nile crocodile inside an MRI machine and scanned its brain while it was listening to classical music. Bach was on the playlist, if you were just wondering about the reptile’s musical tastes.

The study might sound gimmicky but it’s actually very important. The results, for instance, suggest that the fundamental neuronal processing mechanisms for sensory stimuli evolved hundreds of millions of years ago and can be traced back to a common ancestor of all vertebrates.



Brains don’t fossilize, which is a bummer for scientists who would like to know how the most ancient brains function and trace back the evolutionary history of the ultimate biological hardware. Luckily, they have at their disposal the next best thing: crocs. You see, crocodiles have barely changed in the last 200 million years or so, and, as such, they represent the perfect animal model for investigations of ancient neural workings.
脳は化石に残らない(><) それって最古の脳機能がどう機能していたのかを知って、究極的な生物学的ハードウェアの進化の歴史を遡りたい科学者にとって最低なことなんだ。

Researchers led by Felix Ströckens from the Department of Biopsychology at Ruhr University Bochum wanted to investigate how the crocodilian brain might respond to complex sounds, so that they might compare the patterns to those of birds and mammals. To this end, the researchers inserted a Nile crocodile (Crocodylus niloticus) into an MRI machine in order to scan its brain. Yes, science can be very exciting (and dangerous).

Magnetic resonance imaging, or MRI, uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of the inside of your body. Previously, MRI scans have been performed on various mammals, but this is the first time a cold-blooded reptile was put inside an MRI machine, which had to be modified for this study.

As you might imagine, placing a croc inside a very cramped and noisy machine was challenging work.


In order to make sure the croc didn’t move inside the machine for proper scanning, the reptile was sedated and had its snout taped for extra safety.

The fact that the animal is cold-blooded added to the complexity of task since brain scans can be skewed by the animal’s body temperature. Luckily, the researchers were at least fortunate enough to work with very gentle crocs. Perhaps, the selection of sounds that the researchers played, which also included classical music, helped to calm the beasts.

“In the first step, we had to overcome a number of technical obstacles,” said research team member Mehdi Behroozi. “For example, we had to adjust the scanner to the crocodile’s physiology, which differs massively from that of mammals in several aspects.”

The five juvenile crocs used in the study were exposed to various visual and auditory stimuli like flashing red and green lights or random chord noises between 1,000 Hz and 3,000 Hz. To gauge the croc’s response to complex sounds, the researchers played Johann Sebastian Bach’s Brandenburg Concerto No. 4, which had been employed in previous studies that worked with other animals, thus providing a good reference.
実験にかかわった5頭の若い(1歳?)クロコダイルは様々な視覚的聴覚的刺激にさらされた。点滅する赤と緑のライトやランダムに鳴らされる1000ヘルツから3000ヘルツのコードノイズとかである。複雑な音声への反応を計測するのに研究者はバッハのブランデンブルグ協奏曲 第4番ト長調を流した。この曲は以前他のいきものでも効果を示したのである。よって参考としては申し分ない。

The brain scans revealed that different brain areas were activated in the crocodilian brain when the animal was subjected to complex sounds compared to when basic sounds were played. The observed pattern is very similar to that seen in mammals and birds which were exposed to music.This suggests that the structural and functional machinery of this kind of sensory processing appeared hundreds of millions of years ago. This ability was then preserved and passed down the evolutionary family tree.
観測パターンは哺乳類や鳥類が音楽にさらされた時のものとかなり似通っている。このことで示唆されることはこの種の感覚(聴覚)受容プロセスの構造的機能的メカニズムが数億年前にはあったということだ。この能力はそれから保持され進化の家系図に受け継がれたのである。※ワニの祖先は2億4000万年前とされる。特集:シリーズ 地球のいのち ワニ 幻の支配者 2009年11月号 ナショナルジオグラフィック NATIONAL GEOGRAPHIC.JP


“It was technical breakthrough,” Ströckens told Gizmodo. “We could prove that fMRI can be used in reptiles which differ massively in their physiology from mammals or birds (e.g. body temperature and breathing patterns). This will allow future studies to investigate many species which have not been investigated yet with this non-invasive method.”
Researchers from Iran, South Africa, France and Germany participated in the study, which was published in the journal Proceedings of the Royal Society B: Biological Sciences.
語っている。これがきっかけになり、今後の研究が未だに調査されていない多くの種への非侵襲性手法でのやり方への扉になることが断言できる。この研究にはイラン、南アフリカ、フランス、ドイツの科学者が参加し、『Proceedings of the Royal Society B: Biological Sciences』誌に記事が掲載された模様。⇓アブストラクト


Simple auditory stimuli led to signal increase in the rostromedial and caudocentral ADVR.
単純な聴覚刺激では 吻側及び 尾腹部のADVR(前方背側脳室隆起?)への神経交換量が増加した。
Complex auditory stimuli activated additional regions of the caudomedial ADVR.



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