Objective: The Neuroanatomy Core will provide a resource of state-of-the-art neuroanatomic and neuroimaging techniques to the program project. The overall goal of the Neuroanatomy Core is to link neurochemical architecture of rodent model systems with the neuropathologic findings in human SIDS cases to yield a greater understanding of the biological basis of SIDS. Anatomical labeling techniques supported by the Neuroanatomy Core include multiple immunolabeling, anterograde and retrograde tract tracing, combined tract-tracing and immunolabeling, identification and immunolabeling of intra-cellularly labeled cells, and tissue receptor autoradiography. Visualization techniques include conventional brightfield or fluorescence microscopy, as well as confocal imaging. Qualitative and quantitative analyses include 2- and 3-dimensional computer based mapping, quantitative densitometry, and unbiased 2- and 3- dimensional stereology methods.