Alapakkam P Sampath

Professor, Ophthalmology, University of California Los Angeles

Professor, Neurobiology, University of California Los Angeles


Jules Stein A-200

I hold the Grace and Walter Lantz Endowed Chair in Ophthalmology. My research interests have centered on the physiological function of retinal photoreceptor cells, the rods and cones. In particular, I have studied mechanisms of phototransduction activation and regulation, and how the photoreceptor cell output is represented in the retinal circuitry. Since 2005, the major research focus of my independent laboratory has been in using transgenic mice that display perturbations in photoreceptor function, or retinal connectivity, to establish how rod and cone photoreceptors relay light-evoked signals to bipolar cells over a wide range of light intensities. Much of this work has focused on how single-photon responses are transmitted across the retinal circuitry under conditions where few of the rods are generating them. However, more recently the laboratory has endeavored to establish the mechanisms by which both rod and cone photoreceptors function over a wide range of light intensities, and how retinal function is compromised following retinal degeneration.


Member, Molecular, Cellular & Integrative Physiology GPB Home Area, Neuroscience GPB Home Area



Alapakkam P. (Sam) Sampath is a Professor of Ophthalmology and Neurobiology at UCLA, and the Associate Director of the Jules Stein Eye Institute.  After completing his Ph.D. in 1999 in physiology at UCLA, he did postdoctoral fellowships at Stanford and the University of Washington before joining USC as an Assistant Professor in 2005.  He moved his laboratory to UCLA in 2013.  Sam is the Principal Investigator on several NIH grants to study how the retina encodes light entering the eye in both health and disease.  Over the past decade his laboratory has led efforts to determine how the retina encodes visual information under very dim light, or for night vision.  During this time his lab has identified the biological mechanisms that allow our high visual sensitivity, and how these mechanisms malfunction in night blindness.  Sam is the recipient of the Karl Kirschgessner Junior Faculty Award and received a Scholar Award from the McKnight Endowment Fund for Neuroscience.  His current research remains focused on how the photoreceptor cells, the rods and cones, are activated by light and how these signals are processed in the retinal circuity.



A selected list of publications: