title: Contribution of glial-neuronal interactions to the neuroendocrine control of female puberty.
abstract: Mammalian puberty is initiated by an increased pulsatile release of the neuropeptide gonadotropin-releasing hormone (GnRH) from hypothalamic neuroendocrine neurons. Although this increase is primarily set in motion by neuronal networks synaptically connected to GnRH neurons, glial cells contribute to the process via at least two mechanisms. One involves production of growth factors acting via receptors endowed with either serine-threonine kinase or tyrosine kinase activity. The other involves plastic rearrangements of glia-GnRH neuron adhesiveness. Growth factors of the epidermal growth factor family acting via erbB receptors play a major role in glia-to-GnRH neuron communication. In turn, neurons facilitate astrocytic erbB signaling via glutamate-dependent cleavage of erbB ligand precursors. The genetic disruption of erbB receptors delays female sexual development due to impaired erbB ligand-induced glial prostaglandin E(2) release. The adhesiveness of glial cells to GnRH neurons involves at least two different cell-cell communication systems endowed with both adhesive and intracellular signaling capabilities. One is provided by synaptic cell adhesion molecule (SynCAM1), which establishes astrocyte-GnRH neuron adhesiveness via homophilic interactions and the other involves the heterophilic interaction of neuronal contactin with glial receptor-like protein tyrosine phosphatase-β. These findings indicate that the interaction of glial cells with GnRH neurons involves not only secreted bioactive molecules, but also cell-surface adhesive proteins able to set in motion intracellular signaling cascades.
authors.affiliation: Division of Neuroscience, Oregon National Primate Research Center/Oregon Health Sciences University, 505 N.W., 185th Avenue, Beaverton, OR 97006, USA. ojedas@ohsu.edu
authors.forename: Sergio R
authors.initials: SR
authors.lastname: Ojeda
authors.forename: Alejandro
authors.initials: A
authors.lastname: Lomniczi
authors.forename: Ursula
authors.initials: U
authors.lastname: Sandau
mesh_terms: D000818:Animals; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D009457:Neuroglia / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D009490:Neurosecretory Systems / Q000166:cytology / Q000502:physiology*; D011627:Puberty / Q000502:physiology*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D066247:Receptor, ErbB-4; D012741:Sexual Maturation / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology
chemical_list: D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D018698:Glutamic Acid; D007987:Gonadotropin-Releasing Hormone; D018719:Erb-b2 Receptor Tyrosine Kinases; D066247:Receptor, ErbB-4