Perhaps the most important feature of a neuron is its ability to communicate with other cells at synapses. Research in my lab focuses on synaptic transmission in the vertebrate retina. Retinal neurons have distinctive anatomical and physiological p roperties that suggest they employ unique synaptic mechanisms. The long term objective of our research is to understand how retinal synapses are specialized to transmit visual information. The intact retina is complex and it is therefore difficult to st udy the mechanisms of synaptic transmission between retinal neurons. To circumvent this difficulty, we use a simplified culture system containing isolated pairs of retinal neurons. This preparation permits high resolution electrophysiological recording that allows us to directly study the ionic currents involved in synaptic transmission. In addition, we are using immunocytochemistry, calcium imaging, and molecular techniques to study several aspects of synaptic function. At synapses, calcium ions act as the presynaptic trigger for initiation of a cascade of events that culminate in the fusion of synaptic vesicles with the plasma membrane and release of neurotransmitter. Because calcium plays such a critical role in synaptic transmission we are interested in the ways in which calcium is regulated in the presynaptic terminal during synaptic transmission. We are currently examining novel Ca2+ influx pathways as well as the role of mitochondria in shaping local Ca2+ signals. On the postsynaptic side, we are also investigating the role that nitric oxide plays in regulating the sign (inhibitory or excitatory) of synapses between amacrine cells.
B. Hoffpauir, E. McMains, and E. Gleason. (2006) Nitric Oxide transiently converts synaptic inhibition to excitation in retinal amacrine cells. Journal of Neurophysiology 95: 2866-2877.
M. Sen and E. Gleason. (2006) Immunolocalization of mgluRs 1 and 5 in the synaptic layers of the chicken retina. Visual Neuroscience 21: 221-231.
B. Hoffpauir and E. Gleason (2005) Modulation of synaptic function in retinal amacrine cells. Integrative and Comparative Biology, 45: 658-664.
R. Sosa and E. Gleason. (2004) Activation of mGluR5 modulates Ca2+ currents in retinal amacrine cells. Visual Neuroscience 809-818.
S. Crousillac, M. LeRouge, M. Rankin and E. Gleason. (2003) Immunolocalization of TRPC channel subunits 1 and 4 in the chicken retina. Visual Neuroscience 20: 453-463.
B. Hoffpauir and E. Gleason. (2002) Activation of mGluR5 modulates synaptic and whole cell GABAA currents in retinal amacrine cells. Journal of Neurophysiology 88: 1766-1776.