Chapter 23 - Social Memory, Maternal Care, and Oxytocin Secretion, But not Vasopressin Release, Require CD38 In Mice

Abstract

The CD38-dependent cADPR or NAADP signaling pathway of Ca2+ regulation has been demonstrated in cultured anterior pituitary tumor cells. This chapter describes effects of these pathways on posterior pituitary (neurohypophysial) hormone function in accordance with recent results. CD38 has been identified as a transmembrane receptor that triggers proliferation and immune responses in lymphocytes. CD38, thus, is frequently used as a malignancy or differentiation marker in chronic lymphocytic leukemia or HIV infection. CD38 is present in many tissues, such as the brain and pancreas. The intracellular Ca2+ signaling mechanisms underlying oxytocin (OT) or arginine vasopressin (AVP) secretion are not fully understood and the mechanism for OT and AVP may not be the same. To address this issue, this discussion used CD38 gene knockout mice, and discovered that CD38-dependent cyclic ADP-ribose- and nicotinic acid adenine dinucleotide phosphate sensitive intracellular Ca2+ mobilization plays a key role in OT release, but not AVP secretion, from soma and axon terminals of hypothalamic neurons, exerting profound actions on social behaviors. Alteration of CD38 function and the resultant disturbance of only OT secretion may be associated with some forms of impaired human behavior in the autism spectrum disorders.