NMDA can modulate mGnRH secretion from rat hypothalamus

In our in vitro system, the rat hypothalamus is highly sensitive to N-methyl-D-aspartate (NMDA) in secreting mammalian gonadotropin-releasing hormone (mGnRH). Indeed, doses equivalent to and up to 20-times lower than the hypothalamic concentration of endogenous NMDA, can significantly increase the amount of GnRH secreted by incubated hypothalamic tissue. L-glutamate (another excitatory amino acid) can also induce the secretion of mGnRH, and the data show for the first time that the post-synaptic biological potency of NMDA in evoking GnRH release is nearly 100-times higher than that of L-glutamate. Further work is in progress to clarify the molecular mechanisms that underlie NMDA's role in modulating mGnRH secretion and release