Modeling the acceleration sensitive neurons in the pigeon optokinetic system.
Recent physiological findings revealed that about one-third of motion-sensitive neurons in the pigeon's pretectal nucleus encoded the acceleration of visual motion. Here we propose a microcircuit hypothesis, in which the slow adaptive depressions play a significant role in response generating, to account for the origin of the three important properties of the acceleration-sensitive neurons: the plateau-shaped speed-tuning curves, the opposite-signed after-responses (OSARs) and the acceleration sensitivities. The flat plateau within the speed-tuning curves and the OSARs to motion offset observed in experiments are reproduced successfully in simulations, and the simulative responses of the acceleration-sensitive neurons to step changes, ramp changes in stimulus speed and sine wave modulations of stimulus speed are qualitatively consistent with physiological observations. Thus, a biologically plausible substrate for the neurons' classification and the origin of the three properties are provided.
Zhang
Chuan
C
State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing, 100101, P.R. China.
Wang
Yun-Jiu
YJ
Qi
Xiang-Lin
XL
D000054:Acceleration; D000200:Action Potentials / Q000502:physiology / Q000528:radiation effects; D000818:Animals; D010856:Columbidae / Q000502:physiology*; D003198:Computer Simulation; D008959:Models, Neurological; D009475:Neurons, Afferent / Q000145:classification / Q000502:physiology*; D017120:Nystagmus, Optokinetic / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology / Q000528:radiation effects; D013997:Time Factors; D014795:Visual Pathways / Q000502:physiology; D014796:Visual Perception / Q000502:physiology