Molecular Volume Knob (IMAGE) Dartmouth College Caption A 'molecular volume knob' made of analog signals (red) regulates electrical signals in the brain to support learning and memory. Credit Illustration must credit: Michael Hoppa. 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.