literal windows into the brain
Dec. 19th, 2002 12:36 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
novapsycheScientists Study Brain Changes Over Time
Scientists have found a way to track tiny features of individual brain cells in living mice, providing a glimpse at how brains change over time. In one case, they watched the animals' brains rewire after their whiskers were clipped.
The technique will help scientists explore how the brain forms memories and reacts physically to its owner's experiences.
Brain cells called neurons signal each other across tiny gaps, called synapses. The signals are received by tiny spines. Researchers in both studies followed the growth and destruction of the spines over time.
The researchers tracked the spines, which measure less than one twentieth the width of a human hair, using specially bred mice that carry a gene which makes some of their neurons glow. They used laser and electron microscopes to peek through windows implanted in the mouse skulls, or through skull bones thinned with a drill.
In one study, the researchers clipped the highly sensitive whiskers of mice and watched changes in the part of the brain that receives signals from the whiskers. Two to four days after clipping, the number of spines created or lost in that area increased significantly, indicating new synapses were being created and others destroyed, the researchers reported.
Scientists have found a way to track tiny features of individual brain cells in living mice, providing a glimpse at how brains change over time. In one case, they watched the animals' brains rewire after their whiskers were clipped.
The technique will help scientists explore how the brain forms memories and reacts physically to its owner's experiences.
Brain cells called neurons signal each other across tiny gaps, called synapses. The signals are received by tiny spines. Researchers in both studies followed the growth and destruction of the spines over time.
The researchers tracked the spines, which measure less than one twentieth the width of a human hair, using specially bred mice that carry a gene which makes some of their neurons glow. They used laser and electron microscopes to peek through windows implanted in the mouse skulls, or through skull bones thinned with a drill.
In one study, the researchers clipped the highly sensitive whiskers of mice and watched changes in the part of the brain that receives signals from the whiskers. Two to four days after clipping, the number of spines created or lost in that area increased significantly, indicating new synapses were being created and others destroyed, the researchers reported.
![[identity profile]](https://www.dreamwidth.org/img/silk/identity/openid.png){kind=small}
(no subject)
Date: 2002-12-19 06:15 am (UTC)From the Science Daily:
Melodies In Your Mind: Researchers Map Brain Areas That Process Tunes that is donut shaped, which is called a torus.
"The piece of music moves around on the surface of the torus, so we had to figure out a way to pick out brain areas that were sensitive to the harmonic motion of the melody," explains Janata. "We developed two different tasks for our subjects to perform. We then constructed a statistical model that separated brain activation due to performing the tasks from the activation that arose from the melody moving around on the torus, independent of the tasks. It was a way to find the pure representation of the underlying musical structure in the brain."
The two tasks involved 1.) asking subjects to identify an embedded test tone that would pop out in some keys but blend into other keys, and 2.) asking subjects to detect sounds that were played by a flute-like instrument rather than the clarinet-like instrument that prevailed in the music. As the subjects performed the tasks, the fMRI scanner provided detailed pictures of brain activity. The researchers compared where the activation was on the donut from moment to moment with the fluctuations they recorded in all regions of the brain. Only the rostromedial prefrontal area reliably tracked the fluctuations on the donut in all the subjects, therefore, the researchers concluded, this area maintains a map of the music.
"Music is such a sought-after stimulus," says Janata. "It's not necessary for human survival, yet something inside us craves it. I think this research helps us understand that craving a little bit more."
Not only did the researchers find and map the areas in the brain that track melodies, they also found that the exact mapping varies from session to session in each subject. This suggests that the map is maintained as a changing or dynamic topography. In other words, each time the subject hears the melody, the same neural circuit tracks it slightly differently. This dynamic map may be the key to understanding why a piece of music might elicit a certain behavior one time, like dancing, and something different another time, like smiling when remembering a dance.
Janata adds, "Distributed and dynamic mapping representations have been proposed by other neuroscientists, and, as far as we know, ours is the first paper to provide empirical evidence for this type of organizational principle in humans."
(no subject)
Date: 2002-12-19 09:08 am (UTC)I like the pic of the brain halo. :)
(no subject)
Date: 2002-12-19 11:04 am (UTC)of how the human brain works, but I do have a basic
understanding of how it doesn't work. I do know that
my brain craves music, and I have a difficult time
understanding how any human being can live
through one day without music. In having a few "family"
members who never listen to music, I've
observed a frozenness in them in the way in which they
hug or don't want to be touched period.
(Their entire bodies look hungry for stimulation.)
I believe when one deprives the self of music, that
something vital dies inside. Now this is just my opinion,
I have nothing, no data, to back up my observations.
I'm more the intuitive type, I listen to my heart, and most
often I tell my mind to shut up, too much thinking causes
me immense conflict.)
I've shared more, I'm sure, than you wanted to know, but
then that's my nature. I don't detour, and seldom censor,
this has caused me to lose a friend or two…
I've opened up a door here, your chance to run from
your 'new friend' and never look back. ;)
(no subject)
Date: 2002-12-19 04:36 pm (UTC)Besides, you have the same name as my niece. How could I turn away? :)
Re...
Date: 2002-12-20 10:06 am (UTC)I think there's only two or three songs
about Carol, makes me feel left out.)
Did you know that the name Carol means
:::: song of joy :::: la la la :)
In your bio info you said that you are quite silly.
I'm a silly person myself, much of what I say is
said with some silliness, unless I'm clearly distraught
which would be obvious.) I'm often very playful, am
'prone' to stretching the ordinary, below link is an
example of my playful side.
- Link-
http://www.livejournal.com/talkread.bml?journal=tequilasunset&itemid=235623
Re: Re...
Date: 2002-12-23 07:26 pm (UTC)Oh, I meant JuJu. :) My niece's name is Justice, but her nickname is JuJu. (She is the most gorgeous thing.)
Did you know that the name Carol means
:::: song of joy ::::
Cool. :) I love name etymology.
In your bio info you said that you are quite silly.
Well, I haven't been overtly silly in a while. I don't know if that's a consequence of growing older or what. But I have a good laugh with my mom every other day, so I still get my silliness in every so often.
I like your silliness. It's fun. :)