Cover legend: Astrocytes (green) in the supraoptic nucleus of the rat hypothalamus are oriented vertically, with their somata in the ventral-most layer of the nucleus. Their dense processes make direct contact with vasopressin- or oxytocin-releasing magnocellular neurosecretory cells (blue). The astrocytes regulate the activity of supraoptic neurons (white trace), and thus the release of vasopressin and oxytocin. Cover design by Katrina Choe. For more information, see the article by Choe et al. (pages 12518–12527).