An introduction to neurobehavioral toxicology.

The stated objectives of these Target Organ Toxicity Symposia are to review the morphology, physiology, and biochemistry of the particular organ system, describe means used to assess toxicity, evaluate tests used for this assessment, and finally, to propose the application of recent advances to the development of practical test procedures. Basically, the intent is to discuss ways of evaluating the functional integrity of a given organ system. The subject of a previous symposium in this series was the kidney which may serve as a useful departure point for this discussion. The kidney, like other organ systems, is involved in the organism's homeostatic processes and, of course, its primary role in this regard is to regulate the composition of body fluids. To carry out this function, certain input/output relationships must be maintained. Input to the kidney is provided via the renal artery, and various components of this input (in the form of solute material) are processed in different parts of the kidney. Subsequently, an output is obtained via the ureter, i.e., urine. There are many useful approaches to the study of renal toxicology, including the morphology, physiology, and biochemistry of the organ. Certainly, another rather obvious approach is to quantitate the functional output of the organ, that is, to measure urinary output. A graduated cylinder or some equivalent is the only equipment required for such an approach. Of course, more elaborate measurements can be made including quantitation of the exact composition of the output. In this case more time and expense are involved, but certainly more information is obtained. A suggestion to use such a measurement in the study of renal toxicology would in all likelihood be