Differential postnatal development of µ - , 'd' - and x - opioid binding sites in rat brain Paola Petrillo, Alessandra Tavani, Davide Verotta, Linda E Robson and Hans W Kosterlitz, 'Differential postnatal development of µ - , 'd' - and x - opioid binding sites in rat brain' reprinted from 'Developmental Brain Research', 31 (1987), 53 - 58. 1987