Ajithkumar Warrier
Graduate Student
Department of Neurobiology, Physiology & Behavior
Division of Biological Sciences
1107 Life Sciences Addition (LSA)
University of California, Davis
One Shields Avenue
Davis, California 95616
Phone: (530) 752-1816
Fax: (530) 752-5582
Ajith is a fourth year graduate student in the Neuroscience group at UC, Davis. Trained to be a practicing pharmacist in India, he decided to pursue basic research in the US. He started his journey into scientific research in Dr. Linda Hall's lab at SUNY, Buffalo. In 1999, when Dr. Hall moved to UC Davis, he decided to come along with her so that he could continue research on sodium channel accessory proteins in Drosophila. In Davis, he realized that his interests lay elsewhere and decided to join the Wilson Lab and pursue research on synapses in chick amacrine cells using a combination of Ca2+ imaging, electrophysiology, molecular biology, and immunocytochemical techniques.
Recent Work
Ajith has studied Ca2+ stored in the ER and its physiological role in neuronal functioning. In his previous projects, he has identified IP3Rs (inositol trisphosphate receptors) and RyRs (Ryanodine receptors) in amacrine cell dendrites and shown that these receptors are located at distinct sites on the dendrites. This was possible using immunocytochemical techniques with selective antibodies that recognize IP3Rs and RyRs. Using electrophysiology and specific drug treatments, he has determined that IP3Rs control evoked transmission through autapses in cultured amacrine cells. Ryanodine receptors, though similarly capable of Ca2+ induced Ca2+ Release (CICR) do not regulate autaptic transmission induced in the same manner.
Current Project
Ajith is continuing this project to determine the sources of IP3 that are involved in transmitter release. He is chiefly studying Calcium Binding Proteins (CaBPs) which have been shown to function as endogenous IP3R agonists. He has already shown that these proteins are present in amacrine cell dendrites in a punctate manner. Another question that arises out of the previous study is whether the ER is continuous or discrete in these dendrites. Though many researchers have shown that ER in the dendrites is continuous, the differential role of IP3Rs and RyRs in transmission suggest the possibility that these receptors ride on separate stores. To probe this idea, he plans to use molecular biology techniques to express ER Cameleons in cultured amacrine cells. Read more about cameleons in the following reference.
Miyawaki, A., J. Llopis, et al. (1997). “Fluorescent indicators for Ca2+ based on green fluorescent proteins and calmodulin.” Nature 388(6645): 882-7.
