Funds are requested for a JEOL JEM 1200EX/TN-8500, which is a state-of-art transmission electron microscope and image analysis system (Tracor Northern) that is capable of serial reconstruction. All members of the user group work on different preparations in the nervous system, but have a common need for the availability of an electron microscope with sophisticated image processing capabilities, including 3-D serial reconstruction. The projects of 5 of the users involve the injection of horseradish peroxidase into physiologically identified neurons and the subsequent ultrastructural analysis of the synaptic circuitry of the identified neurons. The systems under investigation include the retina, central visual pathways, neural control of the heart and the spinal cord. The sixth user is studying capillaries in the central nervous system. The currently used electron microscopes are old (10 and 15 years), of highly uncertain continued availability, and not capable of the levels of analysis required for modern neuroanatomical studies.
