Neuromodulation: Mechanisms of Induced Changes in the Electrical Behavior of Nerve Cells

Abstract

Abstract A11 neurons are not created equal. Even neighboring nerve cells may be distinct in their electrical properties and exhibit very different patterns of endogenous electrical activity. As we know from the discussion in Part II of this book, these diverse patterns of activity reflect the complement of ion channels that are active under a given set of conditions. The fundamental issue that we address now is the fact that these patterns of electrical activity are not fixed, but are subject to modulation resulting from synaptic or hormonal stimulation. Neurons may undergo long-lasting changes in the shape and amplitude of their action potentials, in the temporal pattern of action potential firing, and in the ways they respond to synaptic stimulation (Fig. 13-1). Such modulation of neuronal electrical properties, mediated by transduction mechanisms, some of which are described in Chapters 11 and 12, not only allow the nervous system to adapt its output in the face of a continually changing environment but also are the basis for many long-lasting changes in behavior. Because neuromodulation underlies the choice of different patterns of behavior at different times, it is of critical importance for the proper functioning of the nervous system.