Analysis of Brain Nuclei Accessible to Ghrelin Present in the Cerebrospinal Fluid

GIMENA FERNANDEZ; AGUSTINA CABRAL; MARIO PERELLÓ

Congreso; Sociedad Argentina de Neurociencias. XXVIII Annual Meeting.; 2013

Ghrelin is a stomach-derived peptide hormone that acts in the brain to regulatemany important physiological functions. Ghrelin receptor, named the growthhormone secretagogue receptor (GHSR), is present in many brain areas with orwithout obvious direct access to ghrelin circulating in the bloodstream. Ghrelin isalso present in the cerebrospinal fluid (CSF) but the brain targets of CSF ghrelin areunclear. Here, we studied which brain areas are accessible to ghrelin present in theCSF. For this purpose, we centrally injected mice with fluorescein-labeled ghrelin(F-ghrelin) peptide tracer and then systematically mapped the distribution of Fghrelinsignal trough the brain. Our results indicated that centrally injected Fghrelinlabels neurons in most of the brain areas where GHSR is present. Also, wedetected F-ghrelin uptake in the ependymal cells of both wild type and GHSR-nullmice. We conclude that CSF ghrelin is able to reach most of brain areas expressingGHSR. Also, we propose that the accessibility of CSF ghrelin to the brainparenchyma occurs through the ependymal cells in a GHSR-independent manner.