Meeting Abstract

33.4  Monday, Jan. 5  Estimation of information transfer rates in highly precise sensory afferents FOX, Jessica L.*; DANIEL, Thomas L.; University of Washington; University of Washington jessfox@u.washington.edu

To coordinate their motion, animals rely on sensory systems to acquire, process, and transmit necessary information from the environment. Dipteran insects use specialized structures known as halteres to detect forces that occur as a result of body motions during flight. The primary afferents extending from haltere mechanoreceptors respond to stimuli with extremely high timing precision, suggesting that they are capable of transmitting information at high rates (Fox and Daniel 2008). Given this high degree of precision, we sought to directly measure the mutual information between a stimulus and the resulting spike train. We recorded the activity of more than 30 haltere primary afferent cells while mechanically stimulating the haltere with band-limited Gaussian white noise. In doing so, we directly measure the rate of information transfer. We found that many haltere primary afferent cells are able to transmit information at a rate of at least 60 bits per second and up to 133 bits per second, significantly higher than the rate found in many visual systems. Additionally, we used the measured jitter in response to repeated sine waves (n = 15 cells) to estimate the bit rate as a function of frequency, allowing us to create a neural tuning curve in the common currency of bits per second. By using this modality-independent metric of neural encoding, we can assess the sensory conduction of haltere primary afferents in the context of other information-processing systems.