Connectome Grants DSIhuman (IMAGE) Washington University in St. Louis Caption A wrench for the Brain Activity Map toolkit? Ever since President Barack Obama announced a new initiative to map all the functional connections in the human brain, scientists have been worrying out loud that we may not yet have tools up to the task. After all, the brain has more than a billion neurons that make more than a trillion connections. Herzog says the technique used in his lab to study the biological clock might be useful for the Brain Activity Map as well. By recording neuronal activity, researchers can look for correlated changes between cells. When neuron 1 increases its firing, neuron 2 might be excited and increase its firing. The problem is knowing if that increase was a coincidence or a consequence. The technique, called BSAC (Between Sample Analysis of Connectivity) reliably reveals functional connections by first describing the statistics of impossible connections. If the two neurons are in different dishes, they cannot communicate so the increased firing of neuron 2 must have been a coincidence. By recording from lots of neurons in independent networks, BSAC defines the weakest possible connections that can be detected within a neural network. This could be useful in mapping connections between pairs of neurons or between brain regions. Credit NIH Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.