Calcium Signaling in Astrocytes and Its Role in the Central Nervous System Injury.

Astrocytes are the most abundant glial cells in the central nervous system (CNS). Due to their extensive processes, they can interconnect with many neighboring cells and play critical roles in regulating synaptic plasticity, integrating neuronal signals, and maintaining the stability of the extracellular environment. These functions are largely dependent on calcium (Ca) signaling. In light of these considerations, the powerful functions of Ca signaling in astrocytes have been actively studied in recent years. This review summarizes the mechanisms related to Ca waves in astrocytes as well as their physiological and pathological functions mediated by various calcium signaling, the characteristics of calcium waves, and the role of Ca in astrocytes in the CNS injuries of spinal cord injury (SCI) and traumatic brain injury (TBI) recently. However, inhibited L-type voltage-gated Ca channels (LTCCs) activity and reduced Ca concentration result in an opposite phenomenon that promoting or reducing astrogliosis. This highlights the importance of focusing not only on Ca⁺ concentration but also on the downstream signaling pathways initiated by Ca⁺. Therefore, we summarize diverse signaling pathways in various physiological and pathological contexts.