An overview of our current highest priorities can be stated simply. The anatomical, physiological, and biochemical complexity of neural circuits challenges the ingenuity of scientists working on the brain. Fortunately, useful simplifications have emerged that bring order to observations previously thought to be unrelated and bring basic neuroscience closer to clinical application. For example, nerve cells in all species use the same mechanisms to generate signals. Likewise, similar molecules determine the birth, maturation and death of nerve cells in humans, monkeys, mice, flies, and worms.
Lower organisms can, therefore, help elucidate mechanisms of human disease.
Another simplification is that the same processes influence nerve cell death in seemingly different conditions. If we can stop cell death in one condition, then the insights gained will, very likely, apply to other disorders as well. Molecular genetics is a unifying force in all biology. Because more than half of our genes are expressed in the brain, the potential contribution of genetics to understanding nervous system disorders is extraordinary. The interplay between genes and the environment reveals that circuits in the mature brain can change to a remarkable degree.