All brain functions are controlled by specific synapses where the release of neurotransmitters triggers a number of signaling cascades in postsynaptic neurons. One of the most important and common events is a transient and very fast intracellular Ca2+ increase. Intracellular Ca2+ increase is fundamental for modulation of gene expression, neuronal survival and plasticity. In this chapter we will discuss the importance of Ca2+ in cells as well as the regulation of physiological functions in various organisms. Additionally, we will consider mechanisms used by the cells for Ca2+ homeostasis and for increasing intracellular Ca2+ concentration. Finally, the role of Ca2+ in neurodegenerative diseases such as Alzheimer’s disease (AD), Amyotrophic lateral sclerosis (ALS), Parkinson disease (PD), Huntington disease (HD) among others will be discussed in this chapter.
Keywords: Calcium, Alzheimer’s disease, Parkinson’s disease, Cellular signaling, neurodegeneration, neurodegenerative diseases, brain, Inositol Trisphosphate, Endoplasmic Reticulum, Voltage gated Ca2+ channels, glutamate receptors, ATP receptors, Amyotrophic Lateral Sclerosis, Huntington’s Disease, Multiple Sclerosis, SERCA pump, Ligand Ca2+ channels, Calcium Dysregulation, Ca2+-ATPase, Plasma membrane.