Regulation of Calcium in the Cerebellum

Abstract

Ca²⁺ is an important ion in central nervous system (CNS) biology, where it plays a critical role in the basic functions of neurons, glia, and other cell types. In CNS neurons, Ca²⁺ is a generator of electrical signals, an inducer and regulator of synaptic transmission, and a second messenger that controls many biochemical processes. Ca²⁺ is also a signal transmitter and second messenger in glial cells. Ca²⁺ levels in neurons and glia are dynamic but judiciously controlled in order to maintain biological processes at a level compatible with life. An excess or deficit of Ca²⁺ can result in cell damage or death. A variety of cellular mechanisms, through a process referred to as Ca²⁺ signaling, enable or contribute to the changes in intracellular Ca²⁺ that are essential for normal cell function, some of which are present in all eukaryotic cells and others that are unique to the functions of a particular class of cells. This chapter will briefly describe the cellular mechanisms that contribute to Ca²⁺ signaling in cerebellar and other CNS neurons. These mechanisms are located throughout the neuron including at presynaptic sites (e.g., axon terminals) where they regulate transmitter release, at postsynaptic sites (e.g., dendrites) where they influence synaptic responses, in the cytosol where they regulate biochemical pathways and other physiological functions, and in the nucleus where they regulate gene transcription. Many of these mechanisms are also expressed in non-neuronal cells.