The central nervous system of a vertebrate organism exhibits a very complex spatial organization structure and function. These relationships are the subject of intense study for over a century, and recent developments in imaging have attracted ever increasing effort devoted to the understanding of brain function. One can produce any number of quantitative images that provide maps of the anatomy and function of nerve tissues. For example, autoradiography can yield functional images (2-deoxy glucose), maps of neurotransmitters receptors (over 100 know types), and gene expression labeled with complementary mRNA (in-situ hybridization). Immunohistochemistry produces maps of a large variety of neuroactive components, such as transmitters.

To illustrate a typical procedure, we describe the mapping of brain function with 2-deoxy glucose (2DG). A rat performing some task is injected with a solution of 2DG radiolabeled with 14C¨ Subsequently, the animal is sacrificed, the brain is cryosectioned (ca. 20 μm), and contact autoradio-grams of these sections are made on X-ray film.