Adaptation of the skin colour to the background light condition in the amphibian Xenopus lae6is is achieved by migration of pigment granules in the skin melanophores, a process regulated by a-MSH secretion from melanotrope cells in the pituitary pars intermedia (PI). a-MSH secretion in turn, is regulated by various stimulatory and inhibitory messengers synthesized in brain nuclei, especially th...
