The development of new molecular imaging techniques has bridged the gap between preclinical and clinical research. During the last decade, the developments in imaging strategies have taken a great leap by the advancements in new imaging scanners, development of pharmaceutical drugs, diagnostic agents, and new therapeutic regimens that made significant improvements in health care. The knowledge gained from imaging techniques in preclinical research can be applicable to the patients. Similarly, the problems from clinical studies with humans can be tested and studied in preclinical studies. The appropriate application of molecular imaging to drug discovery and development can markedly reduce costs and the time required for new drug development. Some imaging techniques, such as computed tomography (CT) or magnetic resonance imaging (MRI), reveal anatomical images, and single-photon emission computed tomography (SPECT), SPECT/positron emission tomography (PET), and PET show functional images. These developing molecular or neuroimaging methods provide increasingly detailed structural and functional information about the nervous system. The basic principles of each technique are described followed by examples of the current applications to cutting-edge neuroscience research. In summary, it is shown that neuroimaging continues to grow and evolve, embracing new technologies and advancing to address ever more complex and important neuroscience questions.