Insulin-Like Growth Factor-1 Inhibits Adult Supraoptic Neurons via Complementary Modulation of Mechanoreceptors and Glycine Receptors
| Autor: | Claude Colomer, Anne Duvoid-Guillou, Françoise Moos, Gérard Alonso, Cécile Monzo, Nicolas Hussy, Jeanne Ster |
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| Rok vydání: | 2005 |
| Předmět: |
Male
Vasopressin Patch-Clamp Techniques Taurine Vasopressins Action Potentials In Vitro Techniques Biology Oxytocin Tritium Inhibitory postsynaptic potential Supraoptic nucleus Receptor IGF Type 1 Receptors Glycine Glial Fibrillary Acidic Protein medicine Animals Premovement neuronal activity Drug Interactions Enzyme Inhibitors Insulin-Like Growth Factor I Glycine receptor Neurons Dose-Response Relationship Drug General Neuroscience Dose-Response Relationship Radiation Glycine Agents Neural Inhibition Long-term potentiation Strychnine Immunohistochemistry Electric Stimulation Rats Androstadienes medicine.anatomical_structure Excitatory postsynaptic potential Neuron Wortmannin Mechanoreceptors Supraoptic Nucleus Neuroscience Cellular/Molecular |
| Zdroj: | The Journal of Neuroscience. 25:2267-2276 |
| ISSN: | 1529-2401 0270-6474 |
| Popis: | In the CNS, insulin-like growth factor-1 (IGF-1) is mainly known for its trophic effect both during development and in adulthood. Here, we show than in adult rat supraoptic nucleus (SON), IGF-1 receptor immunoreactivity is present in neurons, whereas IGF-1 immunoreactivity is found principally in astrocytes and more moderately in neurons.In vivoapplication of IGF-1 within the SON acutely inhibits the activity of both vasopressin and oxytocin neurons, the two populations of SON neuroendocrine cells. Recordings of acutely isolated SON neurons showed that this inhibition occurs through two rapid and reversible mechanisms, both involving the neuronal IGF-1 receptor but different intracellular messengers. IGF-1 inhibits Gd3+-sensitive and osmosensitive mechanoreceptor cation current via phosphatidylinositol-3 (PI3) kinase activation. IGF-1 also potentiates taurine-activated glycine receptor (GlyR) Cl-currents by increasing the agonist sensitivity through a extremely rapid (within a second) PI3 kinase-independent mechanism. Both mechanoreceptor channels and GlyR, which form the excitatory and inhibitory components of SON neuron osmosensitivity, are active at rest, and their respective inhibition and potentiation will both be inhibitory, leading to strong decrease in neuronal activity. It will be of interest to determine whether IGF-1 is released by neurons, thus participating in an inhibitory autocontrol, or astrocytes, then joining the growing family of glia-to-neuron transmitters that modulate neuronal and synaptic activity. Through the opposite and complementary acute regulation of mechanoreceptors and GlyR, IGF-1 appears as a new important neuromodulator in the adult CNS, participating in the complex integration of neural messages that regulates the level of neuronal excitability. |
| Databáze: | OpenAIRE |
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