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"One of the by-products of car production was Fordite, also known as Detroit agate. The colorful layered objects take their name from agate stones for their visual resemblance. But instead of forming from microscopically crystallized silica over millions of years, Fordite was formed from layers of paint over several tens of years." [via.]
In a groundbreaking new study, researchers at the University of California, San Diego erased and then reactivated memories by stimulating neurons in the brains of genetically engineered rats with a series of light pulses that have been previously shown to strengthen or weaken the connections between brain cells. This is the first study to be able to directly show that the strengthening or weakening of these connections, called synapses, is the underlying basis for memory. The study has been published in Nature.
Neurons communicate with each other via synapses, which are the tiny gaps between cells that permit the flow of information in the form of a chemical or electrical signal. Early research found that repeated electrical stimulation of neurons within a brain region called the hippocampus enhanced the ability of these cells to communicate with neighbors. This process is called long-term potentiation (LTP), and it has long been suspected that this is the underlying basis of memory formation. Despite decades of research, however, no one has unequivocally demonstrated that this is the case.
For this study, a team of researchers led by UCSD neuroscientist Roberto Manilow first engineered rats so that their brain cells produced a light sensitive protein which could be activated by a pulse of light delivered by an optical fiber implanted into the brain. They then used this optogenetics to condition the rats to associate pain with optical stimulation by delivering light pulses to certain neuronal populations and then shocking the rats. The rats quickly began to associate the optical stimulation with pain and displayed fear responses when the neurons were stimulated. The scientists were able to demonstrate telltale signs of LTP by looking at chemical changes in the neurons.
Next, the team stimulated the same neurons but with a different, low-frequency sequence of light pulses that had been previously demonstrated to reverse LTP by weakening the synaptic connections, which is known as long-term depression (LTD). When the mice were given the optical stimulation that they originally associated with pain they no longer elicited a fear response, suggesting that the original memory was erased. The team was able to then reactivate the memories by delivering high-frequency light pulses that triggered LTP, and then erase them again. “We were playing with memory like a yo-yo,” Manilow said in a news-release.
The results of this study are therefore finally able to demonstrate a causal link between LTP, LTD and memory. “We can cause an animal to have fear and then not have fear and then to have fear again by stimulating the nerves at frequencies that strengthen or weaken the synapses,” said lead author Sadegh Nabavi in a news-release.
This discovery may also have applications in the field of Alzheimer’s research since, according to Manilow, the beta-amyloid protein fragment that builds up in the brains of Alzheimer’s patients also weakens synapses in a similar manner to how the low-frequency stimulation in this study removed memories. “So this line of research could suggest ways to intervene in this process,” he added. [via.]
Site of the day.
"Lazaretto" by Jack White [Official Music Video]
Tattooed Porcelain Figures by Jessica Harrison.
On work days arise to your labors happily, if you can. And if you can’t, what’s stopping you? Is there something heavy, something difficult in your way? What do you have against what’s heavy and difficult?—That it can kill you.—Alright, so it’s strong and powerful, you know that much about it. And what do you know about what’s easy? Nothing. We have no memory at all of what’s easy. So even if you were permitted to choose, wouldn’t you actually have to choose what’s hard? Don’t you feel how kindred it is to you, related to you through all your loves? Is it not your true home?
And aren’t you in harmony with nature when you choose it? Don’t you think the seed would find it easier to stay in the earth? Don’t the migrating birds have it hard, and the wild who have fend for themselves.
Look: easy things and hard simply do not exist. Life itself is what’s hard. And you want to live, don’t you? So you’re wrong to call it your duty to take on what’s hard. The survival instinct pushes you to do that. So what is your duty? Your duty is to love what’s hard. That you carry the weight doesn’t say much, you have to rock it in its cradle and sing it to sleep and be there when it needs you, and it can need you at any moment.
You have to be so ready to help, so gentle and kind, that you spoil it, spoil your difficult thing like a child, so that it can no longer exist without you, so that it depends on you.
After you’ve brought it to such a state you will no longer want anyone to come take it off your hands.
And you get that far through love. To love is hard. When someone bids you to love, they are laying a great task upon you, but not an impossible one. For they are not calling you to love another person, which is not for beginners; they are not demending from you that you love God, which only the most mature of people can do. They are only calling your attention to what’s hard for you, what is neediest in you and at the same time most fruitful. You see, what’s easy wants nothing from you, but what’s hard waits for you, and there is no strength in you that won’t be needed there, and even if your life is very long not a single day will be left over for what’s easy, what scoffs as your strength.
Go deep inside yourself and build what’s hard. it should be like a house within you, if you yourself are like a land that changes with the tides. Remember, you are not a star, you have no course to follow.
You must be a world unto yourself and with your difficult thing in your center, drawing you to it. And one day, with its weight, its gravity, it will have its effects beyond you, on a destiny, on a person, on God. Then, when it’s ready, God will enter into your difficult thing. And do you know anywhere else where you and He can meet?
- Rainer Maria Rilke