Tanycyte as mediators of kisspeptin effects

Tanycytes are ependymoglial cells in the wall of the third ventricle that play a central role in the regulation of neuroendocrine hormone axes and metabolism. Depending on their location in the ventricular wall, tanycytes have different properties. Our preliminary work in mouse models shows that subtypes of tanycyte are innervated by different neurons. One group of these neurons produces kisspeptin, which is an essential factor in the control of puberty and fertility. Interestingly, the stimulation of different tanycyte subtypes by kisspeptin has differential effects on the hypothalamic-pituitary-gonadal axis and the oestrous cycle of animals. In the proposed project, we first want to characterise the molecular structure of the unusual synaptoid contacts between kisspeptin neurons and tanycytes. Based on this, we want to clarify whether the synaptoid connections between kisspeptin neurons and tanycytes depend on the sex, age and hormone status of the animals. We propose to investigate whether kisspeptin influences the morphology of tanycytes and what effects the tanycytic response to kisspeptin has on puberty, fertility and metabolism of the animals. Answering these questions will be made possible by the collaboration between the two applicants, the exchange of new methods to genetically manipulate tanycyte subtypes and advanced microscopic techniques. In this way, the project will elucidate a previously unknown mechanism of neuroglial interaction and contribute to the understanding of neuroendocrine regulation of puberty and fertility.