We will purchase two Zeiss 510 Meta confocal microscopes for our studies. These microscopes will be configured on fixed-stage upright microscopes and will come with 458, 477, 488, 5t4, 543 and 633 nm laser lines, two internal photomultiplier tubes and a Meta, 32 element spectral detector. The 510 Meta confocal microscope is the instrument of choice for studies because of its ability to detect emission spectra and to unmix overlapping spectra of multiple indicators while performing the high-quality confocal imaging expected of a 510 system. We feel that the Meta detector is a revolutionary concept in microscopy which will significantly facilitate our biological studies; it will permit our investigators to simultaneously express multiple fluorescent proteins in cells and, despite their similarity in emission spectra, to quantitatively identify the contribution of each. With 20 investigators and 34 NINDS projects in this proposed Center, each investigator would have only two hours per week (or each N1NDS project would have just over one hour per week) on the microscope were we to have only one two photon microscope available. Thus the purchase of two of these two-photon microscopes is essential. Because CHOP appreciates the great expense of these microscopes, it has provided $259,835 to alleviate some of the financial burden.