Endocrine Abstracts

Gonadotropin releasing-hormone (GnRH or LHRH) regulates the hypothalamo-pituitary-gonadal (HPG) axis in vertebrates. GnRH neurons that regulate the HPG axis derive from progenitor cells in the nasal compartment and migrate along vomeronasal fibers across the cribriform plate into the forebrain. GnRH neurons migrate over a long route that provides many factors for guidance. Early in their migration, GnRH neurons always follow fibers; if fiber trajectories are altered, GnRH neur...

The defining features of Kallmann's syndrome (KS) are isolated hypogonadotrophic hypogonadism (IHH) and anosmia, the consequences of a GnRH neuronal migratory defect and olfactory bulb agenesis respectively. Additional features in X-linked Kallmann's syndrome (XKI), include unilateral renal agenesis and bimanual synkinesis respectively. XKI results from mutations of KALIG 1, on Xp22.3. The encoded protein anosmin-1, is a hexamodular secreted cell membrane associated extracellu...

Over one hundred years ago Ramon y Cajal proposed that developing axonsmight be guided to their targets by diffusible chemical signals but thefirst evidence that this was possible did not emerge until 1983. Ten yearslater saw the first evidence for diffusible repellent signals that restrictthe territories occupied by axons and the first identified chemorepellent,c...

Recent advances in our knowledge of pituitary development, acquired mainly from animal models, have enhanced our understanding of the aetiology of isolated growth hormone deficiency (IGHD) and combined pituitary hormone deficiency (CPHD). A number of developmental genes known to be important for organ commitment and cell differentiation and proliferation (HESX1, LHX3, LHX4, PROP1 and PIT1) have been implicated in CPHD with or without other sy...