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Dr. Ilan Lampl and Alik Mokeichev.. Brain wires



In the epic endeavor to understand the brain, scientists have suggested a number of theories as to how patterns of basic electrical signals become sensations of taste, sight and sound. A leading theory has now been called into question by Dr. Ilan Lampl of the Weizmann Institute’s Neurobiology Department, in a paper recently published in the journal Neuron.
Neurons – the brain’s “wires” – transmit information around the neural circuit as electrical pulses. The question is: How does the brain translate this information, enabling us to perceive and understand the world?
One theory posits that different types of information are represented by patterned sequences of electrical charges across an array of neurons. A chair and a table, according to this theory, will each generate a distinct pattern within the system of nerve cells for the brain to interpret. Each time the same object is viewed, the neural circuit will create an identical pattern in a precise and controlled manner.
Lampl’s early experiments seemed to support this theory, but he was somewhat puzzled by the observations. “Something didn’t quite add up. How can this system – thousands of neurons communicating through unreliable connections – produce the same sequence of patterns time after time?”
Lampl decided to investigate further. Using anaesthetized rats, he and his research team created software programs for measuring and analyzing patterns generated within the cortex (the structure in the brain involved in higher cognitive processes, believed to produce sensory perception). By applying three different randomization techniques to the data, they were able to determine if the second-long repeating patterns are statistically arbitrary or whether controlled mechanisms must come into play.
When the scientists randomized the data, mixing it up in various ways, they found no differences between the original and the jumbled data in the number of repeating patterns or the time it took for various patterns to repeat themselves. They therefore came to the conclusion that the patterns observed could not be produced in a deliberate manner, but occurred purely by chance. If this is indeed the case, how can the observed phenomenon be explained? If, says Lampl, there is a limited repertoire of electrical patterns, even those that repeat themselves randomly will eventually appear to form ordered arrangements.
Lampl: “From the moment the theory originated in the 1980s, many neuroscientists believed they possessed the key for beginning to understand the workings of the brain. But we have provided strong evidence that what appears to be the precise repetition of patterns is actually erratic. This does not preclude the possibility that such patterns will be found in the future – provided that careful analysis such as ours shows they cannot be attributed to chance.”    
This work has been carried out together with research student Alik Mokeichev of the Institute’s Neurobiology Department and the Ben-Gurion University of the Negev, Dr. Michael Okun of the Institute’s Neurobiology Department and the Hebrew University of Jerusalem, students Omri Barak and Yonatan Katz of the Neurobiology Department, and Dr. Ohad Ben-Shahar of the Ben-Gurion Univeristy of the Negev. 
Dr. Ilan Lampl’s research is supported by the Nella and Leon Benoziyo Center for Neurological Diseases; the Carl and Micaela Einhorn-Dominic Brain Research Institute; the Alhadeff Research Award; the Chais Family Foundation; the Clore Foundation; the Murray H. and Mayer Grodetsky Family Center for Research of Higher Brain Functions; the Dr. Pearl H. Levine Foundation for Research in the Neurosciences; the Henry S. and Anne S. Reich Research Fund for Mental Health; and Mr. and Mrs. Gerald M. Lushing, Beverly Hills, CA. Dr. Lampl is the incumbent of the Carl and Frances Korn Career Development Chair in the Life Sciences.