ITPR2 and Alexander disease: Consequently, the IP3R2 KO mouse model [42], a mutant with altered astrocytic calcium signalling due to the absence of IP3R2, has been at the center of several relevant studies that have revealed important physiological roles of IP3R2 signalling in not only astrocytes [43,44,45,46,47,48,49,50,51] but also in pathophysiological alterations in the context of stroke [52,53], traumatic brain injury [54], and some neurodegenerative diseases, such as Alexander disease [55].