University of Rochester Eye Institute
Krystel R. Huxlin
Assistant Professor
Department of Ophthalmology
Neurobiology & Anatomy
Center for Visual Science
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Ph.D. (1994) B.Sc.Med (1991) |
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Contact Information: E-Mail: huxlin@cvs.rochester.edu University of Rochester School of Medicine and Dentistry 601 Elmwood Ave, Box 314 Rochester, New York 14642 Phone: (585) 275-5495 Fax: (585) 473-3411 |
Research
Using awake-behaving animal models to study physiological optics and neuronal plasticity after damage to the adult visual cortex.
Research Overview
Neural Mechanisms of Visual Recovery after Brain Lesions in the Adult
The goal of this research program is to gain insight into the neuronal changes underlying the recovery of visual functions after brain damage in adulthood. We have developed a behavioral paradigm, which allows training of adult cats to perform visual discrimination tasks with a degree of precision, which, until now, was only possible in human and non-human primates. Preliminary results using this methodology show that unilateral damage to the lateral suprasylvian (LS) cortex in cats produces a specific loss of the ability to integrate local motion signals and extract motion signals from noise. These deficits are associated with specific neurochemical alterations concentrated in low-level visual cortical areas interconnected with LS cortex. Post-lesion visual discrimination retraining leads to gradual recovery of motion perception that is specific to the visual stimuli used during retraining and is restricted largely to the visual field location retrained. Our studies at the cellular and molecular levels (in collaboration with Dr. David Calkins) reveal that visual recovery is associated with particularly strong alterations in the neurochemistry of area 18, one of the low-level visual cortical areas interconnected with LS cortex. Since these changes affect AMPA receptor subunit composition and the expression of other synaptic proteins, we are currently testing the hypothesis that synaptic and connectional reorganization in area 18 may be critical for the recovery process. These results lay the foundation for ongoing studies at the molecular and systems levels of how adult brain circuits are altered and repaired by experience. In collaboration with Drs. Mary Hayhoe, Eric Kelts and Scott Burgin, we are now also working on the development of therapeutic strategies, to promote visual recovery following brain damage in humans.
Advanced Physiological Optics in the Awake-behaving Cat
Laser refractive surgery aims to correct visual problems to the point where glasses and contact lenses are no longer required. The modern version of this surgery uses a laser to trim away corneal tissue, changing its shape and thus correcting a range of optical aberrations. While defocus and astigmatism are relatively well corrected by this procedure, "higher order" optical aberrations, such as spherical aberration and coma, often increase post-operatively for reasons that we do not understand. Because such defects decrease the quality of vision, our laboratory, in collaboration with Drs. David Williams, Geunyoung Yoon, Scott MacRae, Ian Cox and Jay Wang, has developed a unique, animal model in which refractive surgery experiments can be conducted to tease out the causes of surgically-induced optical aberrations. The key attribute of this animal model is that it allows precise measurement of optical aberrations in cats trained to fixate down the optical axis of ophthalmic instruments. Using a specially-modified Shack-Hartmann wavefront sensor and Optical Coherence Tomographer, we have been able to demonstrate that refractive surgery induces similar changes in higher order aberrations and corneal structure in cats and humans.By combining studies of ocular optics and corneal biology in the same animals, our experiments will provide new insights into the biological causes of post-operative increases in optical aberrations. This knowledge is essential if we are to design and test laser ablation algorithms and post-operative strategies to prevent or correct such aberrations following refractive surgery.
Recent Publications
1. Huxlin K.R., Yoon G., Nagy L., Porter J. and Williams D.R. (2004) Monochromatic ocular wavefront aberrations in the awake-behaving cat. Vision Research (In press).
2. Huxlin, K.R. (2004 planned release) "Neurochemical changes underlying motion perception plasticity after visual cortex lesions". In "Reprogramming the Cerebral Cortex: Plasticity Following Central and Peripheral Lesions". S.G. Lomber and J. J. Eggermont (Eds). Oxford University Press.
4. Huxlin K.R. and Pasternak T. (2001) Long-term neurochemical changes after visual cortical lesions in the adult cat. Journal of Comparative Neurology 429: 221 - 241.
5. Huxlin K.R., Saunders R., Marchionini D., Pham H-A. and Merigan W.H. (2000) Perceptual deficits after lesions of inferotemporal cortex in macaques. Cerebral Cortex 10: 671 - 683.
6. Huxlin K.R. and Merigan W.H. (1998) Deficits in complex visual perception following unilateral temporal lobectomy. Journal of Cognitive Neuroscience 10: 395 - 407.
7. Huxlin, K.R. Book Review on: “Cerebral Cortex, Vol 12, Extrastriate Cortex in Primates”, edited by Rockland, Kaas and Peters. Trends in Neurosciences (1998) vol. 21, pp. 499.
8. Wang C., Dreher B., Huxlin K.R. and Burke W. (1997) Excitatory convergence of Y and non-Y information channels on single neurons in the PMLS area, a motion area of cat visual cortex. European Journal of Neuroscience 9: 921 - 933.
9. Huxlin K.R. and Goodchild A.K. (1997) Retinal ganglion cells in the albino rat: revised morphological classification. Journal of Comparative Neurology 385: 309 - 323.
10. Bennett M.R. and Huxlin K.R. (1996) Neuronal cell death in the mammalian nervous system: the calmortin hypothesis [review]. General Pharmacology 27: 407 - 419.
11. Huxlin K.R. and Bennett M.R. (1995) NADPH-diaphorase expression in the mammalian retina after axotomy - a supportive role for nitric oxide? European Journal of Neuroscience 7: 2226 - 2239.
12. Huxlin K.R. (1995) NADPH-diaphorase expression in neurons and glia of the normal adult rat retina. Brain Research 692: 195 - 206.
13. Huxlin K.R., Dreher Z., Schulz M. and Dreher B. (1995) Glial reactivity in the retina of adult rats. Glia 15: 105 - 118.
14. Huxlin K.R., Dreher B., Schulz M., Sefton A. and Bennett M.R. (1995) Effect of collicular proteoglycan on the survival of adult rat retinal ganglion cells following axotomy. European Journal of Neuroscience 7: 96 - 107.
15. Huxlin K.R., Carr R., Schulz M., Sefton A. and Bennett M.R. (1995) Trophic effect of collicular proteoglycan on neonatal rat retinal ganglion cells in situ. Developmental Brain Research 84: 77 - 88.
Recent Conference Presentations
1. Kelts, E.A., Williams, J.M., Feldman, B., Hayhoe, M. and Huxlin, K.R. (2004) Training-induced perceptual recovery after visual cortical stroke. 30th Annual NANOS Meeting, Orlando, FL.
2. Nagy, L.J., MacRae, S.M., Yoon, G., Cox, I. and Huxlin, K.R. (2004) Ocular wavefront aberrations after laser refractive surgery – a comparison of human and cat eyes. ARVO.
3. Williams, J.M. Price, T.M., Funderburk, S. and Huxlin, K.R. (2003) Training-induced alterations in AMPA receptor subunit composition after cortical lesions in adult cats. Society for Neuroscience.
4. Huxlin, K.R., Yoon, G., Nagy, L., Brandon, E., Porter, J., Cox, I., MacRae, S. and Williams, D.R. (2003) Ocular wave-front aberrations in awake cats. ARVO.
5. K.R. Huxlin and T. Pasternak (2002) Temporal characteristics and stimulus specificity of visual recovery after LS cortical lesions in the adult cat. Society for Neuroscience.
6. K.R. Huxlin, G. Yoon, J. Porter, L. Nagy, S. MacRae, I. Cox and D. Williams (2002) Wavefront sensing in an awake, behaving cat model for refractive surgical applications. 23rd CVS Symposium "Engineering the Eye", University of Rochester.
7. T.A. Price and K.R. Huxlin (2001) Differential effect of adult cortical lesions on Glu receptor expression in projection cells and interneurons of the afferent circuitry. Society for Neuroscience.
8. K.R. Huxlin, T. Price and T. Pasternak (2000) Cellular changes associated with visual recovery after cortical lesions in adult cats. Society for Neuroscience.
9. N. McFarland, K. Huxin and S.N Haber (2000) Differential distribution of GAP-43 message in infra- and supragranular layers of the orbital and medial prefrontal cortex. Society for Neuroscience.
Review Articles
1. Bennett M.R. and Huxlin K.R. (1996) Neuronal cell death in the mammalian nervous system: the calmortin hypothesis [review]. General Pharmacology 27: 407 - 419.
Invited Book Review
"Cerebral Cortex, Vol 12, Extrastriate Cortex in Primates",
edited by Rockland, Kaas and Peters, for Trends in Neurosciences
(1998) vol. 21, pp. 499.
PubMed Search
PubMed search results for Dr. Huxlin