The Hypothalamus - Hippocampus Ghrelin Neurons Projected And Hippocampal Microinjection Ghrelin Rats Feeding, Body Weight And Gastric Motility Impact

Objective:The aim of the present study was to investigate whether ghrelin expressed in the hippocamlpal neurons (HIP) and tracking neurofibra pathway between the hippocamlpal neurons and paraventricular nucleus of hypothalamus (PVN), and to explore whether ghrelin can activate pathways in the rat HIP to stimulate gastric motility.Methods:We used sections of brain to observe injected FG sites and distributions retrogradely labeled neurons in the brain. Application hippocampal nuclear injections, record awake free rat gastric motility, food intake and weight change.Results:Retrogradely tracing results:After injection of FG into the HIP or PVN, retrogradely labeled neurons and neurofibra were found in the the HIP or PVN, immunohistochemical staining sections of ghrelin were found two types of labeled neurons in the HIP or PVN, which retrolabeled neurons with FG or CY3 immunopositive. The amplitude of gastric motility in conscious rats was dose-dependently increased by microinjection of ghrelin into HIP, and the effects were reduced by Ghrelin receptor antagonist D-Lys3-GHRP-6.Conclusion:Our findings suggest that ghrelin neurons in HIP may accept peripheral somatosensory afferent inputs from gastric mechanoreceptors of the stomach, and also may acts as a stimulated factor in HIP to regulate gastric motility via some inferior nucleus relay pathway. The results provide insight into the role of Hip in the control of digestion mediated via ghrelin.