Luteinizing hormone releasing hormone (LHRH) neurons in aging female rhesus macaques

Luteinizing hormone releasing hormone (LHRH) elements were demonstrated immunocytochemically in coronal sections of a portion of the left hypothalamus in twenty female rhesus macaques ranging in age from just over two years to over 21 years. This time period includes the juvenile preovulatory phase. The region studied included the retrochiasmatic region as far dorsally as the superior extent of the optic tract and as far posteriorly as the mammillary body. There was a range in total LHRH neurons per animal from 55 to 470. No trends in cell number as a function of age was observed. The range in cell number among the youngest animals (two year olds) was about the same as that in adult (6-15 year olds) and older (20+ year olds) animals. These results suggest that there is no age-related decline in the potential for manufacture of LHRH, at least into the pre-menopausal period, in the female rhesus macaque.