Function and distribution of growth hormone receptor positive neurons in neonatal mouse brain
Objective To study the distribution and function of growth hormone receptor(GHR)positive neurons in neonatal mouse brain.Methods Six GHR-CreERT;mTOMATO/mGFP fluorescent reporter gene mice were selected.All of them were induced with tamoxifen on the 3rd day after birth.On the 10th and 17th day,3 mice were sampled respectively at each time point.The distribution of GHR-positive neurons in the developing brain was observed at different stages.GHR floxed mice were generated.By crossing them with neuron-specific Thy1-CreERT;YFP mice,GHR in neurons was inducingly knocked out.Control mice(GHR fl/fl,4 mice)and conditional knockout mice(Thy1-CreERT;YFP;GHR fl/fl,4 mice)were induced on the 3rd day after birth.Samples were collected on the 10th day for observing the effect of neuronal GHR signaling on brain development.Results The GHR fluorescent reporter gene mice showed that GHR-positive cells were widely expressed in the developing mouse brain.GHR-positive neurons were concentrated in the paraventricular hypothalamic nucleus(PVN).After specifically knocking out GHR in neurons of the developing mouse brain,no significant differences were observed in the areal densities of neurons and various types of glial cells.Conclusion GHR-positive neurons are mainly concentrated in the PVN.Knocking out GHR in neurons of the developing mouse brain can not significantly change the morphology and density of various neural cell types.