LONG-TERM OBJECTIVE: To understand the synaptic, dendritic and network mechanisms of spatiotemporal processing underlying the computation of visual motion.
SPECIFIC AIMS :
The aim i s to provide a cellular- and systems-level understanding of spatiotemporal processing in the tectal SGC-I motion pathway, thereby providing insight into general neural strategies for visual motion processing.
The specific aims are (1) to determine to what extent the retino-tectal dynamics renders the SGC-I response to dynamic visual stimuli largely insensitive to the details of the retinal transformation, (2) to investigate the functional role of dendritic spike initiation and nonlinear dendritic interaction for the neural analysis of space-time pattern in the presynaptic population activity, and (3) to investigate the functional role of neural structure and connectivity for the population coding of motion with interdigitating sets of spiking dendrites. RESEARCH DESIGN AND METHODS: Synaptic, dendritic, and network mechanisms are critical for information processing in all vertebrates, but have been difficult to elucidate in mammals because of anatomical limitations. Therefore a chick tectal slice preparation has been developed which has two features that help to circumvent these limitations: (a) The extensive and sparse spatial distribution of tectal SGC-I neuron dendrites allows the spatiotemporal synaptic stimulation of selected dendritic endings in the slice. (b) Tectal SGC-I neurons receive monosynaptic inputs from a subpopulation of retinal ganglion cells at their dendritic endings. Further, tectal SGC-I neurons are sophisticated spatiotemporal integrators of retinal representations of dynamic visual stimuli and previous tectal SGC-I studies indicate phasic retino-tectal synaptic dynamics, dendritic spike generation in response to synaptic stimulation, and highly nonlinear dendritic interaction of multiple synaptic inputs. The central component of this research program consists of in vitro synaptic stimulation and whole-cell recordings. The interpretation of the in vitro results is supported with computational modeling. HEALTH-RELATEDNESS: The understanding of spatiotemporal processing at the level of synapses and dendrites in a visual pathway provides the key for the pharmacological intervention of visual perceptual impairments.
| Dellen, Babette; Wessel, Ralf; Clark, John W et al. (2010) Motion processing with wide-field neurons in the retino-tecto-rotundal pathway. J Comput Neurosci 28:47-64 |
| Caudill, Matthew S; Eggebrecht, Adam T; Gruberg, Edward R et al. (2010) Electrophysiological properties of isthmic neurons in frogs revealed by in vitro and in vivo studies. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 196:249-62 |
| Caudill, Matthew S; Brandt, Sebastian F; Nussinov, Zohar et al. (2009) Intricate phase diagram of a prevalent visual circuit reveals universal dynamics, phase transitions, and resonances. Phys Rev E Stat Nonlin Soft Matter Phys 80:051923 |
| Dellen, Babette K; Clark, John W; Wessel, Ralf (2009) Contextual interactions in a generalized energy model of complex cells. Spat Vis 22:301-24 |
| Shao, Jing; Lai, Dihui; Meyer, Ulrike et al. (2009) Generating oscillatory bursts from a network of regular spiking neurons without inhibition. J Comput Neurosci 27:591-606 |
| Meyer, Ulrike; Shao, Jing; Chakrabarty, Saurish et al. (2008) Distributed delays stabilize neural feedback systems. Biol Cybern 99:79-87 |
| Brandt, Sebastian F; Wessel, Ralf (2007) Winner-take-all selection in a neural system with delayed feedback. Biol Cybern 97:221-8 |
| Khanbabaie, Reza; Mahani, Alireza S; Wessel, Ralf (2007) Contextual interaction of GABAergic circuitry with dynamic synapses. J Neurophysiol 97:2802-11 |
| Brandt, Sebastian F; Dellen, Babette K; Wessel, Ralf (2006) Synchronization from disordered driving forces in arrays of coupled oscillators. Phys Rev Lett 96:034104 |
| Mahani, Alireza S; Khanbabaie, Reza; Luksch, Harald et al. (2006) Sparse spatial sampling for the computation of motion in multiple stages. Biol Cybern 94:276-87 |
Showing the most recent 10 out of 12 publications
