- The role of Snapin in neurosecretion: snapin knock-out mice exhibit impaired calcium-dependent exocytosis of large dense-core vesicles in chromaffin cells. Tian, J.H., Wu, Z.X., Unzicker, M., Lu, L., Cai, Q., Li, C., Schirra, C., Matti, U., Stevens, D., Deng, C., Rettig, J., Sheng, Z.H. J. Neurosci. (2005)