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...

Introduction: Pain as a complex process in the CNS has been extensively studied by many researchers. It has been found that pain is controlled by certain pathways in the CNS, one of most important of which is the descending noradrenergic system. The pathway begins with Locus Coeruleus (LC) nucleus and ends in the spinal cord. In this study, formalin test was used as a chemical and tonic pain...