“Up All Night” is an irreverent look at modern parenthood. Christina Applegate stars as Reagan Brinkley: loving wife, successful career woman, life of the party and, most recently, mom. Determined not to compromise her career or cool reputation to the cliches of motherhood, Reagan adjusts to life with a baby and returns to work with the support of her stay-at-home husband, Chris (Will Arnett). As Reagan and Chris figure out their new life, self-doubt, sleep deprivation and the pressure of today’s parenting protocols rattle their confidence. What’s more, the endless needs of Reagan’s boss, ambitious but vulnerable talk-show host Ava (Maya Rudolph), threaten to throw Reagan off balance.