Neuroendocrine Aging in the Female Rat: The Changing Relationship of Hypothalamic Gonadotropin-Releasing Hormone Neurons and N-Methyl-d-Aspartate Receptors**Preliminary versions of this work were presented at the 28th and 29th Annual Meetings of the Society for Neuroscience (Abstracts 110.11 and 777.10). This work was supported by the Brookdale Foundation (to A.C.G.), NIH Grant 1-PO1-AG16765–01 (to A.C.G. and J.H.M.).