Combining Ca2+ imaging with -glutamate photorelease

This article describes simple configurations and methods for measuring optical Ca(2+) signals in response to photorelease of -glutamate. This photostimulation allows activation of postsynaptic glutamate receptors without activation of voltage-gated Ca(2+) channels, thereby permitting the separation and analysis of different Ca(2+) components. We give details of basic microscopy configurations and recommend tools for efficiently illuminating the preparation while preserving the healthy condition of the tissue. We also suggest methodological procedures and discuss linear optics for achieving simultaneous imaging and uncaging using two-photon illumination.