University of Edinburgh

Neurons within the brain communicate with one another using an enigmatic code that we have yet to crack. The rich and diverse patterns of electrical signals that comprise this code underlie our many cognitive abilities. Although neuronal signalling is complex, it may obey general principles of information communication. In particular, there is a trade-off between the speed and accuracy with which messages can be conveyed. Consider speaking over the telephone in an emergency: one could of course talk very quickly, but then not all of it would be accurately heard. Therefore, the rate at which we speak should depend on the situation, including how much time is available, and how catastrophic communication errors would be. This is certainly true in our everyday lives, but it may also hold true for neural communication in the brain.

During his fellowship, Zahid will be examining whether trade-offs in speed and accuracy apply to neural communication. To record neural signals, Zahid will genetically modify cells in the rodent brain so that they fluoresce when they are electrically active (see video). This will allow him to directly visualize the neural code in awake and behaving animals.

He will use this technique, along with computational tools, to study the messages that are being sent and received by neurons when the brain is engaged in a series of behavioural tasks. A trade-off between the speed and accuracy of neural communication, if discovered, would represent a novel and fundamental principle for understanding information processing in the brain.

The video shows neurons within the rodent visual cortex that have been genetically modified to fluoresce when electrically active. Neurons can be seen to “light up” when visual stimuli (shown on the top right) are presented to the animal. Credit: Sur Lab, MIT.