Neuroendocrinology and ageing

Neuroendocrinology is a large field and this review concentrates on age-associated changes in the hypothalamo-pituitary axis and related systems. Most studies have been carried out in males, usually with ill-defined subject selection, and often have not included the very elderly. The hypothalamo-pituitary-adrenal and thyroid axes are well preserved, though some minor changes have been observed. Age alterations are frequently best observed through detailed analysis of the pattern of secretion such as with the reduced nocturnal secretion of prolactin. The gonadotrophic hormones increase with age and some of the changes can be manipulated through the controlling systems. Growth hormone and insulin-like growth factor-1 reduce with age and some of the physical alterations associated with these reductions can be reversed by the administration of recombinant growth hormone.