Dmitri Rusakov & Jeffrey Diamond Collaboration
Title: Excitatory transmission and Ca2+ dependent astrocytic signaling
There is a rapidly growing body of evidence suggesting a functional relationship between Ca2+ signals generated in glia (in particular astrocytes) and the functioning of nearby excitatory synapses. Interference with endogenous Ca2+ homeostasis inside individual astrocytes has been shown to affect synaptic transmission and its use-dependent changes in the hippocampus. However, establishing the causal link between source-specific, physiologically relevant intracellular Ca2+ signals, the astrocytic release machinery and the consequent effects on synaptic transmission has proved difficult. Improved methods of Ca2+ monitoring in situ should be essential for resolving the current ambiguity in understanding the underlying Ca2+ signalling cascades.
Patch-clamp electrophysiology in astrocytes and neurons combined with two-photon excitation imaging and uncaging in acute slices (hippocampus and retina); fluorescence lifetime imaging of Ca2+ signals inside individual neurons and astrocytes; probing intracellular nano-diffusion with time-resolved fluorescence anisotropy imaging; Monte Carlo simulations of molecular mobility and receptor reactions in complex extracellular environment.