There are three major goals in the Animal Neurobiological Core: 1. To provide the environment, expertise and equipment necessary to accomplish each Specific Aim of Projects 1 and 2 of this competitive renewal application for our NIH-NIDA Research Center. 2. To provide the expertise and equipment, where necessary, to nurture Pilot Projects that involve tissues from animals at a specific time in the stages of drug exposure, withdrawal or re-exposure. 3. To provide training in studies involving animals exposed to drugs, withdrawn or re-exposed. The training may include some or all aspects of animal study: the ethical issues of research with animals, the handling of specific rodent species and drug administration; behavioral monitoring of loeomotor activity; specific behavioral tests such as the development of conditioned place preference or elevated plus maze; the analysis of behaviors such as stereotypy after the administration of the psychostimulant cocaine; details of small animal surgery; techniques of microdialysis in specific regions of the rodent brain; the techniques of monitoring self-administration of heroin or cocaine in both the mouse and the rat; the preparation of protocols for submission to the Institutional Animal Care and Use Committee of the Rockefeller University.