Rausser College of Natural Resources congratulates professors Gregory Aponte, Lynn Huntsinger, Isha Ray, and David Zilberman on their recent retirements from UC Berkeley. We thank them for their commitment to their students and their fields, and for their years of service to the University.
Gregory Aponte has conducted extensive research into the gut-brain axis, specifically how the intestine and brain communicate using gut hormones and the body’s nervous system. This pathway influences biological processes including the release of bioactive molecules that affect metabolism and feeding behavior. His research has centered on elucidating how dietary nutrients can act as signaling molecules before entering the body to become metabolites.
Early in his career, Aponte was the first researcher to discover that a dietary nutrient can directly act as a signaling molecule before it is absorbed. He demonstrated that specific dietary free fatty acids can directly trigger receptor-mediated signaling pathways upon contact with the external surface of intestinal cells. This results in the release of peptide-YY, a hormone known to affect pancreatic and intestinal functions as well as food intake behavior. Aponte’s lab later identified the LPA5 receptor as a dietary protein receptor, part of a larger family of receptors expressed on the surface of sensory nerves in the intestinal lymphatic vessels. The Aponte lab showed that these receptors enabled sensory nerves (in contact with the intestinal lymph) to respond to molecules—including dietary components and hormones found in the lymphatic fluid—by releasing neuropeptide signals known to modulate central nervous system and peripheral tissue activity. This pathway has expanded the concept of the gut-brain axis by identifying a neurolymphocrine system.
Aponte earned his PhD in nutrition from UC Davis and joined the Berkeley faculty in 1986. More recently, Aponte’s lab has characterized the sensory nerves activated by nutrient-responsive peptides such as GLP-1 and GIP, mapping how signals from the gut reach the brain along vagal and spinal pathways through a neurolymphocrine system.
Gregory Aponte
Lynn Huntsinger studies the interactions between ecology, land use, and cultural practice on working landscapes across California and the American West. Specifically, her research examines how ranchers, conservationists, and Indigenous communities shape ecosystems through grazing, fire, and stewardship, and how the environmental benefits and agricultural goods of rangelands can be co-produced and synergistic, rather than conflicting. Huntsinger has also studied the management and conservation of oak woodlands in both California and Spain, as well as pastoralist lifeways and the impacts of agricultural policy change across the grasslands of China’s pastoral regions.
Huntsinger joined the UC Berkeley faculty in 1989, the same year she earned her PhD from the College of Natural Resources. Her work improving public perception and on-the-ground management of natural resources by centering land managers and users as partners in conservation has been recognized by numerous professional organizations. Huntsinger is the 2020 recipient of the W.R. Chapline Research Award, bestowed by the Society for Range Management for exceptional and sustained research accomplishments in range science and associated disciplines. Her dedication to protecting the environment and advancing conservation of open spaces and natural resources earned her the California Rangeland Trust’s 2021 Conservation Impact Award. And in 2025, the California Cattlemen's Association awarded Huntsinger their Gordon K. Van Vleck Memorial Award, recognizing her significant contributions to advancing rangeland conservation and sustainable public lands grazing, and for training a new generation of students on the economic and ecological value of livestock grazing.
Lynn Huntsinger
Isha Ray’s research spans the intersections of water, gender, society, and the governance of common-property resources—with a sustained focus on the role technology plays in advancing or hindering sustainable development and social equity. Much of her work centers on access to safe and affordable water for low-income people across the globe. She and her students have worked alongside communities in India, China, Tanzania, and Mexico, as well as across California’s Central Valley.
Ray came to UC Berkeley in 1999 as a Ciriacy-Wantrup Postdoctoral Fellow and joined the Energy and Resources Group faculty in 2002. She is the former Associate Dean for Equity and Inclusion at Rausser College, a previous co-director of the Berkeley Water Center, and an affiliate of the Institute for South Asia Studies. Beyond the university, Ray regularly shares her expertise as an adviser to the United Nations Educational, Scientific and Cultural Organization (UNESCO), UN Women, and the UN Environmental Program. She is a member of the Lancet medical journal’s Commission on Water, Sanitation and Hygiene (WASH), which aims to reimagine and reconstitute WASH as a central pillar of public health and a pathway to gender equality and environmental justice.
Isha Ray
Agricultural economist David Zilberman’s work spans topics including water policy, the economics of innovation, biotechnology, bioenergy, climate change, agricultural supply chains, and the bioeconomy. He joined the Department of Agricultural & Resource Economics (ARE) in 1973 as a PhD student and, after graduating, was hired as a professor. Throughout his career, Zilberman edited 25 books and co-authored more than 400 peer-reviewed journal articles in publications ranging from Science to The Quarterly Journal of Economics. His economic models have shaped major policy debates, including the development of water markets in California, pesticide regulation, and the worldwide adoption of agricultural biotechnology.
Zilberman has been widely recognized in the field of agricultural economics and is the 2019 recipient of the Wolf Prize in Agriculture, often referred to as the agricultural equivalent of the Nobel Prize. He is also a member of the National Academy of Sciences, a fellow of the American Association for the Advancement of Science, and a past president of the Agricultural & Applied Economics Association.
At Berkeley, Zilberman served as ARE chair and director of the Giannini Foundation of Agricultural Economics. A driving force behind international training and education programs, he chaired the dissertation committees for nearly 60 PhD candidates, many of whom have since become leading scholars in the field. Zilberman co-founded the College’s Beahrs Environmental Leadership Program in 2001 and was the founding director of Berkeley’s Master of Development Practice program. He will continue to serve the college as a professor of the graduate school.
David Zilberman