Learning and Memory: Basic Mechanisms

Previous chapters in this book described the various components of nerve cells and their biophysical and biochemical properties as well as the ways in which neurons are connected to each other to process information and generate behavior. This chapter describes the ways in which these components and properties of the nervous system are used to mediate two of its most important functions: learning and memory. Neuroscientists are beginning to have a reasonably detailed cellular and molecular theory of simple forms or aspects of learning and memory. The field is experiencing great synergism from the fusion of two research traditions. The "bottom-up" approach begins by exploring neuronal modifications that seem to be promising candidate mechanisms for supporting plasticity in circuits that control a behavior(s) of interest. (This approach was described in Chapter 18.) The "top-down" approach described in this chapter starts with the behavioral facts and laws, identifies the critical circuits, and then localizes the neuronal mechanisms responsible for changes in the modified circuits.