Changes in synaptic inputs to ARC KNDy neurons and MBH GnRH neurons during the preovulatory surge. The present data shows that glutamatergic (as shown by vGlut2 inputs; 1) and other inputs, as represented by synaptophysin-labeled terminals (2), to ARC KNDy neurons are increased at the time of the preovulatory surge. In addition, KNDy (kisspeptin/vGlut2) labeled inputs onto MBH GnRH neurons are increased at the time of the surge (3). The present data also shows that although POA kisspeptin neurones receive vGlut2, synaptophysin and KNDy inputs to their cell bodies, the numbers of these inputs are not significantly different between luteal phase and the surge.