The production of the second messenger molecules diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) is mediated by activated phosphatidylinositol-specific phospholipase C enzymes. This phospholipase activity is very sensitive to calcium. May be important for formation and maintenance of the neuronal network in the postnatal brain. a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-4,5-bisphosphate) + H2O = 1D-myo-inositol 1,4,5-trisphosphate + a 1,2-diacyl-sn-glycerol + H(+) Activity is stimulated by GNB1:GNG2. Localized predominantly at the plasma membrane. Specifically detected in the brain, with higher level in cerebral cortex, olfactory bulb and hippocampus (at protein level). Expressed in the pyramidal cells of the hippocampus, but also in eye and lung. Expressed at 2 weeks after birth but barely detected 1 week after birth. Increased expression during brain development. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Truncated N-terminus. Aberrant splicing. Truncated C-terminus.