生物谷报道：当你与久未谋面的朋友重逢时会给你带来意外的惊喜，你可以称之为“雪崩”。最新研究认为，大脑雪崩可有助于人的记忆。2004年，美国卫生研究院的研究人员将老鼠的大脑组织在微电极下观察发现，脑细胞会在这种称为“神经元雪崩”的方式下相互激活。
现今新的研究理论认为，大脑雪崩可能是最佳的信息存储。如果这一结论成立的话，一些影响神经系统的化学物质在一定的时候会使人类的记忆问题得到改善。
生物物理学家、现任印地安那大学生物复杂性学会教授John Beggs先生说：“当大多数人想起雪崩时，他们会对某些事物无限想像。但雪崩有大有小，并且较小的就是人们最常见的，这正是我们在脑细胞中发现的。”
Beggs说，当雪崩从山上掉下来到达半山腰时，似乎是为人力不可控的，但实际上，它是被特定的因素所控。这些同样的因素也同样控制着表面上似乎不相关的事件（如森林大火和地震），还有一些大脑的神经系统的活动。所以这些现象，从生物细胞到国家经济，都是复杂性科学研究的范畴。
生物复杂性是一个涉及物理、化学、计算机科学、数学以及生命科学的交叉性学科。这项研究由国家科学基金会（NSF）资助（http://www.bioon.com/）。
Brain 'avalanches' may help store memories
Meeting a friend you haven't seen in years brings on a sudden surge of pleasant memories. You might even call it an avalanche. Recent studies suggest that avalanches in your brain could actually help you to store memories. Last year, scientists at the National Institutes of Health placed slices of rat brain tissue on a microelectrode array and found that the brain cells activated each other in cascades called "neuronal avalanches."
New computer models now suggest that these brain avalanches may be optimal for information storage. If so, certain neurochemical treatments might someday improve life for people with memory problems. A report of this work will be published Feb. 4 in the journal Physical Review Letters.
"When most people think of an avalanche, they imagine something huge," said biophysicist John Beggs, now a professor in the Biocomplexity Institute at Indiana University Bloomington, who helped perform the NIH experiments. "But avalanches come in all sizes, and the smaller ones are most common. That's just what we found in the brain cells."
An avalanche roaring down a mountainside may seem to be wildly out of control, but actually it is governed by certain equations. These same equations also govern such seemingly unrelated events as forest fires and earthquakes -- as well as some neural activity in the brain, Beggs said. All are examples of phenomena that can be studied with the new science of complexity, which deals with all kinds of complex systems ranging from living cells to national economies.
Biocomplexity is a cross-disciplinary field involving physics, chemistry, computer science, mathematics and the life sciences. A description of the IU Biocomplexity Institute, headquartered in IU Bloomington's Department of Physics, is available at http://www.indiana.edu/~iufcs/issue7/solving.shtml.
To find out the possible benefits of brain avalanches, Beggs and IU senior Clay Haldeman simulated the spreading activity of brain cells in a computer model. When the activity was tuned to mimic the avalanches seen in brain tissue, a large number of stable activity patterns appeared. Stable activity patterns are thought to be important for memory, since they have been recorded in the brains of monkeys and rats after they perform memory tasks, Beggs said.
"The fact that the most stable activity patterns appeared when the network of brain cells was also producing avalanches hints that the brain may actually use avalanches to store information," Beggs said.
"This work might ultimately help human memory," he explained. "If our computer simulations apply to networks of human brain cells, then it would be desirable to have your brain in a state where it naturally produces avalanches. In the laboratory, we can apply neurochemicals to defective networks of rat brain cells, gently easing them into a state where avalanches occur. These chemicals suggest treatments that might someday improve information storage in people with memory problems."
This research was funded by the National Science Foundation.
From Indiana University（http://www.bioon.com/）
