The morphology core will provide a facility for the preparation and interpretation of the morphology (gross and microscopic) of the nicotinic acetylcholine receptor mutant animals to be investigated in this program project, i.e. the alpha3, alpha7, beta2, and alpha7L247T mutant animals, and possibly other mutant animals as they become relevant to the aims of the project. The animals will be examined at autopsy for gross anomalies, and individual organs, but particularly the brain, spinal cord, peripheral ganglia, and the heart will be studied using histology, histochemistry, immunocytochemistry, in situ hybridization, receptor autoradiography, and ultrastructural studies. The specialized work of the core, after completion of baseline studies of the mutant animals, will be requested by Drs. Dani, De Biasi, and Paylor when their projects raise specific questions pertaining to the localized chemoarchitecture of the heart, ganglia, and specific brain nuclei. The morphology core will be located at two sites, in Dr. Armstrong's research laboratory in the Feigin Center at Texas Children's Hospital, and in Dr. Jim Patrick's laboratory in the Division of Neuroscience in the Smith Research wing at Baylor College of Medicine. The two facilities are within 10 minutes walking distance, and are connected by email to other investigators of the Program Project and to each other. Dr. Armstrong will coordinate the studies in the two facilities and Dr. Broide will direct the studies, particularly the in-situ hybridization studies which will be carried out in the Patrick laboratory.