Rebecca Meyer Brown Professor

Mrinalini Hoon, PhD

Assistant Professor, Dept. of Ophthalmology and Visual Sciences

McPherson Eye Research Institute

Madison, WI

Dr. Hoon’s Research Project

How synaptic connections ‘wire’ the developing and diseased retina

Current Research Interests

Retinal neurons communicate with each other and integrate information at specializations called synapses. Synapses are dynamic and responsive to circuit formation events and degenerative processes that occur during circuit perturbation. Dr. Hoon’s research combines high-resolution imaging, electron-microscopy, electrophysiological, gene-profiling and transgenic techniques to study how synapses in the inner retina are established and how this leads to stereotypic connectivity patterns between retinal neurons during development and maturation. Dynamic interplay of cell-dependent and network activity-dependent processes come together to ensure precise retinal synaptic connectivity that supports visual perception. An understanding of the cellular, molecular, and activity-dependent mechanisms that establish retinal synaptic connections during development together with transgenic models of retinal disease and degeneration, will enable Dr. Hoon’s Lab to reveal how alterations (and breakdown) of circuit assembly mechanisms degrades synaptic integrity and functional responses in disease. Understanding the mechanistic basis of synaptic re-organizations and dysfunction can enable formulation of novel therapeutic approaches to restore circuit function during degeneration and disease.

Dr. Hoon’s previous work has shown that inner retinal synapses are capable of plasticity and re-arrangements in response to variations in network and circuit activity levels and the long-term goal of her Lab is to harness this intrinsic capability of plasticity to rejuvenate retinal synaptic connections and function during disease and degeneration conditions.

Prior Brown Professor (until 6/30/18)

Aparna Lakkaraju, PhD

Assistant Professor

Ophthalmology and Visual Sciences

University of Wisconsin

Madison, WI

Dr. Lakkaraju’s Research Project

Insight into the Cellular Basis of Retinal Degenerative Diseases

Current Research Interests

Dr. Lakkaraju studies the cells of the retinal pigment epithelium (RPE), which perform critical homeostatic functions that are crucial for the health of the retina and for vision. It is now believed that the RPE is the site of initial insult that eventually culminates in vision loss in many retinal diseases including macular degeneration. Work from Dr. Lakkaraju’s laboratory has shown that with age, RPE cells accumulate abnormal amounts of cholesterol, which causes intracellular traffic jams and compromises cell function. They are now investigating how the RPE handles cholesterol, how proteins and lipids are transported within these cells, and how essential housekeeping functions are impacted during aging, chronic stress and inflammation.

Long-term research goals: (i) to understand the pathology or retinal degenerative diseases at a cellular level using biochemistry, cell biology and high-resolution, high-speed live microscopy of healthy, aging and diseased RPE (from human donors, non-human primates, rodents and pigs); and (ii) to use this information to identify novel drug targets and investigate whether existing drugs like statins can help preserve vision in the aging or diseased retina.