Neuroanatomical Tract Tracing

This new edition presents readers with the latest information on neuroscience. This book explores the advances in molecular techniques, genomics and proteomics and the progress in fluorescence.

The first two editions of this title had a tremendous impact in neuroscience. Between the Second edition in 1989 and today, there has been an explosion of information in the field, including advances in molecular techniques, such as genomics and proteomics, which have become increasing important in neuroscience. A renaissance in fluorescence has occurred, driven by the development of new probes, new microscopes, live imagers, and computer processing. The introduction of new markers has enormously stimulated the field, moving it from tissue culture to neurophysiology to functional MRI techniques.

Times of dramatic progress in brain research have often been correlated with the development of new and powerful techniques that have changed the kinds of questions one can ask. An historical example may illustrate the point. More than 50 years ago, Nissl studies (Ferraro, 1928) showed that extensive forebrain lesions resulted in chromatolysis and cell loss in the sub­ stantia nigra; thus, it was suggested that the substantia nigra gave rise to projections into the basal forebrain. In the late 1950s, another clue emerged, this time linking observations from the field of neuropathology with a dis­ covery in experimental neuropharmacology (Carlsson, 1959a,b; Ehringer and Hornykiewicz, 1960). It had long been recognized that patients with Par­ kinson's disease suffered neuronal loss in the substantia nigra and that their symptoms were somehow related to striatal dysfunction. Thus, when flu­ orescent catecholamine assays were developed and combined with pharma­ cological and neuropathological studies of Parkinson's disease, the dopamin­ ergic nature of the illness was shown. A bit later, Falck and Hillarp (Falck et at. , 1962) developed a fluorescent histochemical method to visualize mono­ amine-containing cells in the brain; this technique was soon applied to show that the rich dopaminergic terminal field in the striatum derived from neu­ rons in the substantia nigra (Anden et at. , 1964). In the following decade, refinements in the histofluorescent method and the development of sensitive silver impregnation methods permitted a detailed light microscopic explo­ ration of the dopaminergic nigrostriatal system.

This volume seeks to familiarize readers with a diverse range of technologies and approaches for probing neuron and circuit architecture, and, when possible, to attach detailed protocols to help guide readers toward practical application. From classical lipophilic dye and conjugated lectin tracing techniques, to electrophysiological, in vivo imaging, viral tract tracing, and emerging genetic methods to mark, manipulate, and monitor neural circuits, Neural Tracing Methods: Tracing Neurons and Their Connections includes reference to an arsenal of tools and technologies currently being implemented in model systems ranging from flies to mice. Written for the popular Neuromethods series, chapters include the kind of detail and key implementation advice that ensures successful results in the laboratory. Essential and authoritative, Neural Tracing Methods: Tracing Neurons and Their Connections collects a comprehensive compilation of chapters authored by inventors and expert users, that describes state-of-the-art neuronal tracing and functional analysis methods in order to aid researchers in continuing this vital pathway of study.

Neuroanatomical Research Techniques discusses developments in major neuroanatomical research techniques. The book is organized into four parts. Part I deals generally with the preparation and study of brain tissue. It includes a chapter on the microscope, discussing optical magnification, limitations of microscopy, and optical contrasting methods. Other chapters summarize basic techniques for tissue preparation and sectioning; present guidelines for a number of standard, but essential, staining procedures; and present sophisticated and contemporary computer techniques that are proving to be invaluable as neuroanatomy evolves from a qualitative to a quantitative discipline. Part II deals with techniques often used for the study of normal tissue. These include the Golgi method, fluorescence histochemistry, techniques for staining single neurons, and the use of the electron microscope. Part III presents techniques for studying intrinsic connections of the nervous system. These include techniques for silver impregnation of degenerating fibers; autoradiographic technique for studying axonal projections; and somatopetal movement of horseradish peroxidase as a tool for studying connections and neuron morphology. Part IV discusses the interpretation of results from neuroanatomical research techniques and presents examples of the applications of neuroanatomical methods to major problems in physiological psychology.