die bohne der nacht ([info]nixietube) wrote,
@ 2004-02-16 15:23:00
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Worms and fish in my brain
The cerebellum is a highly-folded bit of brain lying underneath the occipital lobe towards the back of the head. The word cerebellum means "little brain", and it accounts for around 11% of the entire brain. On top of the cerebellum is a region called the vermis, which means worm. It looks vaguely like a worm and it is exceedingly cute. This is currently my favorite part of the brain.

Nobody quite knows what the cerebellum does. It is known that it has something to do with motor function, since people with cerebellar damage cannot make accurate movements. Movements tend to be larger or smaller than intended, and the motion is jerky since coordination between joints breaks down. The cerebellum also receives input from Ruffini endings, which are sensors that respond to the stretching of the skin. I will post more about Ruffini endings in a separate livejournal entry, since they are quite interesting too. There are some animals with extremely large cerebellums, though, which use cerebellar structures for other purposes. The best example is the mormyrid fish.



These fish are weakly electric, and they generate an electric field around their bodies. They analyze deformations in the electric field to sense objects around them.

Almost the entirety of their brains consist of cerebellum. Here is a picture of the mormyrid fish brain. The regions colored blue are cerebellar. Mormyrid cerebellums are outright obese!





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bizarre
[info]pwilk
2004-05-21 01:56 pm UTC (link)
I also have a huge cerebrum which I use to locate prey.

from a random URL:
It has also been discovered that the fish seemingly obey a master frequency allocation agenda, where each species is assigned to a different frequency band and each individual emits frequency found within the respective band. If two fish of similar frequencies should happen to meet, one will shift its frequency, an act known as "jamming avoidance response". However, if there exists a large amount of species in a particular river, it may interfere with the agenda, in which case a new form of frequency control may be derived.

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