This is an omnibus project that covers a number of studies on development, validation, refinement, and applications of methods for measuring physiological and biochemical processes in functional and structural units of the nervous system in vivo in animals and man. The [14C]iodoantipyrine) method for measuring local cerebral blood flow and the [14C]deoxyglucose method for measuring local cerebral glucose utilization are examples of methods previously developed in this project for use in animals and which were subsequently adapted for use in man with PET and H215O and 18FDG, respectively. We are now applying these methods to determine the basic chemical and physiological mechanisms that mediate the functional activations of brain blood flow and metabolism that are now so extensively used to study cognitive and other functions as well as to models of normal and abnormal conditions of brain function (i.e., hypoglycemia, glucoprivation, chronic bromide intoxication., etc.). During this last year we initiated studies to adapt the radioactive deoxyglucose method for use with MRI spectroscopy which, if successful, would obviate the need for blood sampling and the use of radioisotopes.