We have recently described how the network of non-endocrine folliculostellate (FS) cells may form a new route for rapid long distance communication in the anterior pituitary. However, the role of this cell network in the fine-tuning of the excitable endocrine cells remains enigmatic. The aim of this proposal is to assess how these cells influence pituitary physiology. To achieve this goal, two complementary and parallel approaches will be pursued. In the first one, the behaviour of both endocrine and FS cells will be studied in a novel model recently developed in the host laboratory, where Growth-hormone Releasing Factor (GRF) secreting neurons have be selectively targeted with a neurotoxic transgene, inducing a secondary GH-deficient dwarf phenotype.
Electrophysiological recordings, calcium imaging and hormone measurements will be performed in pituitary slices of these animals. In the second approach we will attempt to generate a transgenic mouse model in which FS cells will be specifically ablated in a time-controlled manner. The study of pituitaries lacking FS cells using static (immunostaining of different endocrine cell types, measurement of hormone contents) and dynamic methods (electrophysiology, calcium imaging, hormone assays on slice perfusates) will provide new insights into the role of the FS cell network in coordinating pituitary function.