The Angelucci Laboratory

angelluci

Alessandra Angelucci's research focuses on identifying neuronal circuits that underlie functional properties of neurons in the visual cerebral cortex and, ultimately, visual perception. The laboratory uses electrophysiological recording of cortical neurons and co-injecting neuroanatomical tracers to map neuronal response properties onto the underlying anatomical structure. To determine the broader functional organization of specific cortical circuits, optical imaging of neuronal populations is combined with injections of anatomical tracers.

At the early stages of visual processing, the retina and brain deconstruct visual scenes into a series of elementary features and attributes, such as color, orientation of line segments, direction of motion, ocularity and spatial location. These properties are segregated in different cortical areas. Research in the lab is currently directed towards understanding how and where in the visual cortex visual signals arising from distant locations in the visual world are integrated into a coherent percept. Specifically, we are studying neural circuits that might underlie long range interactions across visual space and their role in visual perception. A second major line of research is aimed at identifying neuronal circuits that mediate cross-talk between segregated functional streams specialized in processing visual attributes such as color, form and motion.

photo of brain patches

Patterns of feedback from
higher cortical areas to
visual cortex.

Neurons in visual cortex respond to stimuli in a small region of the visual space called the receptive field center. Visual stimuli outside the center (the surround) do not excite the cell, but can suppress the cell's response to visual stimuli in its RF center. The surround plays an important role in our perceptual ability to distinguish a visual object from background. Understanding the brain circuits that generate center and surround responses is an important step in understanding how the normal brain"sees" and what goes wrong when vision is impaired.

Education: M.D., University of Rome, "La Sapienza," ItalyPh.D., Massachusetts Institute of Technology, Cambridge, MA

Academic Appointments: Associate Professor of Ophthalmology & Visual Sciences-University of Utah School of Medicine (tenured); Adjunct Associate Professor of Bioengineering

chart of visual response

A. Circuits in the visual cortex that generate the receptive field center and surround of cortical neurons.
B. Neural network model of center-surround responses in visual cortex.

Patient Care Significance

photo of Neural patterns in the primate retna

Neuronal patterns in
the primate retina.

Work in this laboratory is essential if we are to understand how vision actually occurs in the brain and how we might reproduce it. Retinal degenerations, glaucoma and eye traumas often produce such devastating eye damage that only a cortical prosthesis could restore vision. Our lack of knowledge of the complex organization of visual cortex and our inability to reproduce patterns of signaling required by cortex have prevented such "synthetic vision" from becoming a reality. The Angelucci Laboratory is the Moran Eye Center's lead in developing this knowledge, making us unique among eye centers world-wide.

A sample of major publications from the Angelucci Laboratory

Lund J. S., Angelucci A., and Bressloff P. (2003) Anatomical substrates for functional columns in primary visual cortex. Cerebral Cortex, 12:15-24.

Angelucci A., Levitt J.B., Walton E., Hupé J.M., Bullier J. and Lund J.S. (2002) Circuits for local and global signal integration in primary visual cortex. J. Neurosci. 22: 8633-8646.

Angelucci A. and Bressloff P.C. (2006) The contribution of feedforward, lateral and feedback connections to the classical receptive field and extra-classical receptive field surround of primate V1 neurons. Prog. Brain Res. 154:93-121.

Angelucci A. and Sainsbury K. (2006) The contribution of feedforward thalamic afferents and corticogeniculate feedback to the spatial summation area of macaque V1 and LGN neurons. J. Comp. Neurol.: In Press.

Schwabe L., Angelucci A., Obermayer K. and Bressloff P.C. (2006) The role of feedback in shaping the extra-classical receptive field of cortical neurons: a recurrent network model. J. Neurosci. In press.