Our laboratory uses anatomical and physiological tools to study the functional organization of the mammalian visual system. In particular, we are interested in how visual information is processed and transmitted from one level of the visual pathway to the next.

Along the visual pathway, from retina to extrastriate cortex, neurons become increasingly selective to the patterns of light - the visual stimulus - that are excitatory. The goal of our laboratory is to understand the neural circuitry responsible for generating these selective responses. In addition, we are also investigating the dynamics of these neural circuits to determine what role activity patterns play in influencing neuronal responses.

Traditionally, systems neuroscience has relied on single electrodes to characterize the activity of individual neurons in the brain. For researchers studying the visual system, the activity of individual neurons is recorded while animals are presented with various visual stimuli. By correlating neural responses with visual stimuli, one can ascertain the optimal visual stimulus for any given neuron. While this approach has proven extremely successful over the years and has provided the foundation for our understanding of the neural mechanisms of vision, the single- electrode approach is limited in the extent that we can only infer how populations of neurons behave together in a neural network. With recent progress in multielectrode technology, visual neuroscience is now primed and ready for the next major conceptual advancement: discovering how populations of neurons interact to code and communicate information. In particular, we need to determine the patterns of synaptic activity that convey information within each brain region as well as from one region to the next.

In an ongoing study, we are investigating the relationship between ascending and descending connections made between the thalamus and visual cortex. In an effort to determine the functional role(s) of these connections, we are using multielectrode arrays to record the responses of neurons that are synaptically connected. By recording simultaneously the responses of synaptically connected neurons, in vivo, we can relate neural connection to neural function. In other words, we can discover the rules that govern the connections from one level to the next, and how these connections determine new visual response properties.

Our research is funded by the NIH, the NSF, the McKnight Foundation, the Esther A. and Joseph Klingenstein Foundation, and the Alfred P. Sloan Foundation.

Teaching Interests:
Systems Neuroscience, Neurobiology of Vision, Neuroanatomy, Human Physiology.

Courses Taught:
NSC 201 Neuroanatomy - Term(s): Fall
NSC 222 Systems Neuroscience - Term(s): Winter
NPB 101 Human Physiology - Term(s): Winter
NSC 261B Visual Neuroscience - Term(s): Winter

Publications:

Briggs F, and Usrey WM. (2009) Parallel processing in the corticogeniculate pathay. Neuron 62:135-146.

Briggs F, and Usrey WM. (2008) Emerging views of corticothalamic function. Current Opinion in Neurobiology 18:403-407.

Alitto HJ, and Usrey WM. (2008) Origin and dynamics of extraclassical suppression in the lateral geniculate nucleus. Neuron 57:135-146.

Rathbun DL, and Usrey WM. (2008) The geniculo-striate pathway. In: Encyclopedia of Neuroscience. Eds, Binder MD, Hirokawa N, Windhorst U, and Hirsch MC. Springer-Verlag. Heidelberg, Germany.

Briggs F, and Usrey WM. (2008) Corticothalamic connections: structure and function. In: Encyclopedia of Neuroscience, 4th ed. Elsevier. Amsterdam, The Netherlands.

Reid RC, and Usrey WM. (2008) Vision. In: Fundamental Neuroscience, 3rd Edition. Eds, Squire LR, Roberts JL, Spitzer NC, Zigmond MJ, McConnell SK, Bloom FE. Academic Press. San Diego.

Briggs F and Usrey W (2007) Cortical activity influences geniculocortical spike efficacy. Frontiers in Integrative Neuroscience 1:1-5.

Rathbun DL, Alitto HJ, Weyand TG, and Usrey WM. (2007) Interspike interval analysis of retinal ganglion cell receptive fields. Journal of Neurophysiology 98:911-919.

Briggs F, and Usrey WM. (2007) A fast, reciprocal pathway between the lateral geniculate nucleus and visual cortex. Journal of Neuroscience 27:5431-5436.

Briggs F, and Usrey WM. (2007) Temporal properties of feedforward and feedback pathways between the thalamus and visual cortex. Thalamus and Related Systems 3:133-139.

Alitto HJ, Weyand TG, and Usrey WM (2005) Distinct properties of visually evoked bursts in the lateral geniculate nucleus. Journal of Neuroscience 25:514-523.

Alitto HJ, and Usrey WM (2005) Dynamic properties of thalamic neurons for vision. Progress in Brain Research 149:83-90.

Moore BD, Alitto HJ, and Usrey WM (2005) Orientation tuning, but not direction selectivity, is invariant to temporal frequency in primary visual cortex. Journal of Neurophysiology 94:1336-1345.

Alitto HJ, and Usrey WM (2004) The influence of contrast on orientation and temporal frequency tuning in visual cortex. Journal of Neurophysiology 91:2797-2808.

Alitto HJ, and Usrey WM (2003) Corticothalamic feedback and sensory processing. (2003) Current Opinion in Neurobiology. 13:440-445.

Usrey WM, Sceniak MP, and Chapman B (2003) Receptive fields and response properties of neurons in layer 4 of visual cortex. Journal of Neurophysiology 89: 1003-1015.

Usrey WM. (2002) The role of spike timing for thalamocortical processing. Curr Opin Neurobiol 12:411-417.

Usrey WM. (2002) Spike timing and visual processing in the retinogeniculocortical pathway. Philos Trans R Soc Lond B Biol Sci 357:1729-1737.

Reppas JB, Usrey WM, and Reid RC (2002) Saccadic eye movements modulate visual responses in the lateral geniculate nucleus. Neuron 35:961-974.

Alonso J-M, Usrey WM, and Reid RC (2001) Rules of connection for neurons in the lateral geniculate nucleus and visual cortex. Journal of Neuroscience 21:4002-4015.

Usrey WM, Alonso J-M, and Reid RC (2000) Synaptic interactions between thalamic inputs to simple cells in visual cortex. Journal of Neuroscience 20:5461-5467.

Usrey WM, Reid RC (1999) Synchronous activity in the visual system. Annual Review of Physiology. 61:435-456.

Usrey WM, Reppas JB, and Reid RC (1999) Specificity and strength of retinogeniculate connections. Journal of Neurophysiology 82:3527- 3540.

Usrey WM, Reppas JB, and Reid RC (1998) Paired-spike interactions and synaptic efficacy of retinal inputs to thalamus. Nature 395:384-387.

Alonso J-M, Usrey WM, and Reid RC (1996) Precisely correlated firing in cells of the lateral geniculate nucleus. Nature 383:815-819.