Biography & Introduction
Shu-Rong Wang: 1959-1964, Department of Biophysics, University of Science and Technology of China; 1977-1978, Brain Research Institute of Zurich University, Switzerland; 1986-1998, Director of the Institute of Biophysics, Chinese Academy of Sciences; 1986-1990, President of the Biophysical Society of China; 1988-1997, Chairman, CAS Laboratory for Visual Information Processing; 1986-present, Research Professor; 1987-1989, Member on Editorial Board of Visual Neuroscience; 2006-present, Member on Advisory Board of Journal of Comparative Physiology A.
Research Field: Neuronal mechanisms underlying visual information processing, with particular emphasis on physiological properties and modulation of receptive fields in visual neurons, encoding and detection of visual motion, eye movements and their effects on visual perception, and centrifugal modulation.
(1) Neuronal circuits underlying eye movements and saccadic suppression. In daily life, humans and other foveate animals move their eyes frequently to rapidly search for or smoothly track a target of interest, or make optokinetic and vestibule-ocular reflexes. Our studies on homing pigeons have found that rapid eye movement (saccade) signals originate from the brainstem raphe complex and slow ones from two optokinetic nuclei including the nucleus of the basal optic root in the accessory optic system and the pretectal nucleus lentiformis mesencephali. The traditionally named the fast-phase of optokinetic nystagmus is actually a saccade with a shorter duration. Before the onset of a saccade, raphe neurons send signals to oculomotor neurons to make a saccade and they also send efference copies of the motor signals or corollary discharges to telencephalic neurons via the optokinetic nuclei and visual thalamus. As a result, the blurred retinal images caused by saccades are suppressed by corollary signals and thus the visual word maintains clear and stable.
(2) Neuronal mechanisms for detecting visual motion and generating illusory motion. Humans and other animals move often in the environments containing a variety of objects and thus the ability to detect visual motion is vital for survival. We have found that tectal neurons compute the time-to-collision of an approaching target whereas thalamic cells compute the distance-to-collision of an approaching surface. Pretectal cells can encode all three physical parameters of visual motion, i.e. direction, speed, and acceleration. In a broad range of speeds, the firing rates of these cells depend on the changes of speeds over time (acceleration) but not on speed per se. In addition, they respond equally to real and illusory contours. Some of them produce inhibitory (excitatory) after-responses to cessation of prolonged motion in the preferred (null) directions. Because their excitatory and inhibitory receptive fields possess opposite directionalities, after-responses in one direction may create illusory motion in the opposite direction.
(3) Visual properties and modulation of receptive fields. The receptive field of a visual cell is a region in space or on the retina, stimulation of which can change the cell’s activity. Thus its visual properties and modulation are key problems for studying visual information processing. We have found that the nucleus isthmi in vertebrates are a visual center and identified synaptic nature, transmitters and receptors in the tecto-isthmic system. The magnocellular and parvocellular divisions of the avian nucleus isthmi are separate and they modulate the excitatory and inhibitory receptive fields of tectal neurons, revealing a dual modulation of receptive fields. On the other hand, all the visual cells in a tectal column converge onto an isthmic cell and their excitatory receptive fields form the elongated excitatory receptive field of an isthmic neuron, revealing neuronal mechanisms underlying the formation and modulation of an elongated receptive field and orientation selectivity.
（4）Neuronal circuitry for centrifugal modulation in visual information processing. Visual information is transmitted and processed from the retina to the telencephalon where visual perception results. Meanwhile, the brain also sends messages back to the retina via the centrifugal pathway, which originates from the isthmo-optic nucleus in ground-feeding birds such as pigeons. We have found that tectal axons contact isthmo-optic neurons in a one-to-one fashion mediated by glutamate (AMPA receptors) and nitric oxide. Electrical synapses and field effects may play essential roles in synchronizing neuronal activity within the nucleus. Taken together with the facts that the isthmo-optic nucleus receives input mainly from the dorsal retina via tectum and projects directly to the ventral retina, topographic modulation of tectal activity by isthmo-optic neurons implies that this structure may be involved in switching visual attention to the predator when it appears in the sky.
Selected papers published in recent 5 years：
1. Yan Yang, Peng Cao, Yang Yang, Shu-Rong Wang. Corollary discharge circuits for saccadic modulation of the pigeon visual system. Nature Neuroscience 11 (2008) 595-602. [Evaluated by Faculty of 1000 Biology]
2. Yang Yang, Yan Yang, Shu-Rong Wang. Neuronal circuitry and discharge patterns controlling eye movements in the pigeon. The Journal of Neuroscience 28 (2008) 10772-10780.
3. Da-Peng Li, Qian Xiao, Shu-Rong Wang. Feedforward construction of the receptive field and orientation selectivity of visual neurons in the pigeon. Cerebral Cortex 17 (2007) 885-893.
4. Yu-Qiong Niu, Qian Xiao, Rui-Feng Liu, Le-Qing Wu, Shu-Rong Wang. Response characteristics of the pigeon’s pretectal neurons to illusory contours and motion. The Journal of Physiology –London 577 (2006) 805-813 [Feature in Physiology News 67 (2007) 27-28].
5. Le-Qing Wu, Yu-Qiong Niu, Jin Yang, Shu-Rong Wang. Tectal neurons signal impending collision of looming objects in the pigeon. European Journal of Neuroscience 22 (2005) 2325-2331.
6. Peng Cao, Yong Gu, Shu-Rong Wang. Visual neurons in the pigeon brain encode the acceleration of stimulus motion. The Journal of Neuroscience 24 (2004) 7690?7698. [Evaluated by Faculty of 1000 Biology]
7. Shu-Rong Wang. The nucleus isthmi and dual modulation of the receptive field of tectal neurons in non-mammals. Brain Research Reviews 41 (2003) 13?25. [Cover Article].