Contact Information
Email
Lab Website
(615) 343-4538
Medical School U3218;
Office T2302
Research Area
Education
B.A., University of Colorado (Psychology, major; Biology, minor), 1964
Ph.D., Duke University, 1973
Curriculum Vitae
Advising
- Walter Jermakowicz
(Graduate Student) - Yaoguang Jiang
(Graduate Student) - Keji Li
(Graduate Student) - Roan Marion
(Graduate Student)
Societies
- Society for Neuroscience
- The Association for Research in Vision and Ophthalmology
- FASEB
- American Association of Anatomists
- Middle Tennessee Chapter for Society for Neuroscience
- Visual Sciences Society
Vivien Casagrande
Professor of Cell and Developmental Biology
Professor of Ophthalmology and Visual Sciences
Professor of Psychology
The overall goal of our research is to understand how the visual thalamus and cortex interact to construct our perceptual world.
The first project explores the unconventional proposal that the primary sensory information received by the visual cortex from the visual thalamus [e.g., the lateral geniculate nucleus (LGN)] is not purely visual but rather visual information, primed by inputs from other sensory modalities. In this project, we hypothesize that the primate brain achieves fast and accurate decision-making in part due to its ability to focus, right from the beginning, on relevant aspects of inputs from all sense organs without appreciating all the details presented by each sense organ. Our specific hypothesis is that auditory and visual information are combined in a task dependent manner in the visual thalamus before this message is processed in cortex.
In a second project, we test the hypothesis that all thalamic nuclei contain some cell groups that act as drivers (send the main message) and some that act as modulators for multiple cortical areas, thus mediating the generation of an array of diverse cortical functions. The thalamus is not simply a passive relay to cortex. Instead, just as primary visual cortex (V1) depends on LGN, the secondary visual area (V2) and the middle temporal visual area (MT) depend on a combination of dedicated pathways through the thalamus (e.g., pulvinar) and direct feedforward connections from V1.This arrangement allows new properties to emerge at both the thalamic and cortical levels through dynamic loops.
A third project focuses on communication between cells in different areas of visual cortex and examines how visual messages are coded and transmitted from lower to higher visual areas and what the role of feedback is in this process.
We use a variety of electrophysiological, anatomical, and imaging approaches to address these questions including single unit and multielectrode recording in both anesthetized and awake behaving primates, light, electron microscopic and confocal examination of cells and circuits, optical imaging of intrinsic signals and pharmacological manipulation. Our laboratory also has had a long standing interest in the evolution of the visual system. Therefore, we continue to use a comparative approach to examine for similarities and differences in the organization of the visual system in a variety of primate species.
Representative Publications
- 2001-2008 Older Publications are available at the lab website
- Khaytin, I, Xin Chen, D.W. Royal, O. Ruiz, W.J. Jermakowicz, R.M. Siegel and Vivien A. Casagrande, (2008) Functional organization of temporal frequency selectivity in primate visual cortex. Cerebral Cortex 18: 1828-1842.
- Jermakowicz, W.J. and Casagrande, V.A. (2007) Neuronal networks a century after Cajal in A Century of Neuroscience Discovery: Reflecting on the 1906 Nobel Prizes to Golgi and Cajal. In Brain Research Reviews (L. Swanson, ed.), Elsevier, pp.265-284.
- Boyd, J.D., I. Khaytin, and V. A. Casagrande (2007) Comparative approach to study of the evolution of mammalian visual system. In Evolution of the Nervous System (A. Butler,ed.), in press.
- Casagrande, V.A., I. Khaytin, and J. Boyd (2007) What the evolution of color vision tells us about the function of parallel visual pathways in primates. In Evolution of the Nervous System (A. Butler, ed), in press.
- Casagrande, V. A., F. Yazar, K.D. Jones, and Y. Ding (2007) The morphology of the koniocellular (K) axon pathway in the macaque monkey. Cerebral Cortex Advance Access, published on January 10, 2007.
- Xu, X,, Anderson, T.J., Casagrande, V.A. (2007) How do functional maps in primary visual cortex vary with eccentricity? Journal of Comparative Neurology 501, 741-755.
- Casagrande, V.A., I. Khaytin, I., and J. Boyd (2006) The evolution of parallel visual pathways in the brains of primates. In Evolution of the Nervous System (T.M. Preuss and J. Kaas, eds.), vol. 4, pp. 87-108.
- Ruiz, O., D. Royal, G. Sary, X. Chen, J. D. Schall, and V. A. Casagrande (2006) Low-threshold Ca2+associated bursts are rare events in the LGN of the awake behaving monkey. Journal of Neurophysiology 95:3401-3413.
- Elston, G.N., R. Benavides-Piccione, A. Elston, B. Zietsch, J. DeFelipe, P. Manger, V. Casagrande and J. Kaas (2006) Specializations of the granular prefrontal cortex of primates: implications for cognitive processing. Anatomical Record Part A 288A:26-35.
- Royal, D. W., Gy. Sary, J.D. Schall, and V.A. Casagrande (2006) Correlates of motor planning and integration across visual fixations in the macaque monkey lateral geniculate nucleus (LGN). Experimental Brain Research 168:62-75.
- Xu, X., Collins C.E., Khaytin, I., Kaas J. H., and V. A. Casagrande (2006). Unequal representation of cardinal versus oblique orientations in the middle temporal (MT) visual area. Proceedings for the National Academy of Sciences 103(46):17490-95.
- Casagrande, V.A., Royal, D.W., Sary, Gy. (2005) Extraretinal inputs and feedback mechanisms to the lateral geniculate nucleus (LGN). In The Primate Visual System: A Comparative Approach (Jan Kremers, ed.) Hoboken, New Jersey: John Wiley and Sons, pp. 191-206.
Honors
- 1967-1968; 1970-72 NIH Predoctoral Traineeships
- 1972-1973 NIH NRSA Postdoctoral Fellowship
- 1977-1980 Academic Investigator Salary Award
- 1981 The Charles Judson Herrick Award for meritorious contributions to comparative neurology, presented by the American Association of Anatomists
- 1981-1986 Research Career Development Award
- 1998 President, Cajal Club
- 2006 AAAS Elected Fellow