Browse by author
Lookup NU author(s): Dr Peter Simmons
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
We investigate coding in a locust brain neuron, DNI, which transforms graded synaptic input from ocellar L-neurons into axonal spikes that travel to excite particular thoracic flight neurons. Ocellar neurons are naturally stimulated by fluctuations in light collected from a wide field of view, for example when the visual horizon moves up and down. We used two types of stimuli: fluctuating light from a light-emitting diode (LED), and a visual horizon displayed on an electrostatic monitor. In response to randomly fluctuating light stimuli delivered from the LED, individual spikes in DNI occur sparsely but are timed to sub-millisecond precision, carrying substantial information: 4.5–7 bits per spike in our experiments. In response to these light stimuli, the graded potential signal in DNI carries considerably less information than in presynaptic L-neurons. DNI is excited in phase with either sinusoidal light from an LED or a visual horizon oscillating up and down at 20 Hz, and changes in mean light level or mean horizon level alter the timing of excitation for each cycle. DNI is a multimodal interneuron, but its ability to time spikes precisely in response to ocellar stimulation is not degraded by additional excitation. We suggest that DNI is part of an optical proprioceptor system, responding to the optical signal induced in the ocelli by nodding movements of the locust head during each wing-beat.
Author(s): Simmons PJ, de Ruyter van Steveninck RR
Publication type: Article
Publication status: Published
Journal: Journal of Experimental Biology
Year: 2010
Volume: 213
Issue: 15
Pages: 2629-2639
Print publication date: 16/07/2010
ISSN (print): 0022-0949
ISSN (electronic): 1477-9145
Publisher: The Company of Biologists Ltd.
URL: http://dx.doi.org/10.1242/jeb.043547
DOI: 10.1242/jeb.043547
Altmetrics provided by Altmetric
