Glucose-sensitive neurons in the rat arcuate nucleus contain neuropeptide Y.
Glucose is known to regulate the activity of the hypothalamic feeding centers. Neuropeptide Y (NPY)-containing neurons in the hypothalamic arcuate nucleus (ARC) have been implicated in the stimulation of feeding. We examined the presence of glucose-sensitive neurons in the ARC and their coincidence with NPY-containing neurons. Cytosolic Ca2+ concentration ([Ca2+]i) in single ARC neurons isolated from rat hypothalamus was measured with fura-2 fluorescence imaging; the cells were then stained immunocytochemically with an anti-NPY antiserum. Lowering the glucose concentration from 10 to 1 mM increased [Ca2+]i in 36 out of 180 neurons (20%), the majority of which (34 neurons, 94%) were immunoreactive for NPY. In conclusion, the ARC contains glucose-sensitive NPY-containing neurons. The suggested role of these neurons is to transduce a reduction in the glucose concentration in the brain to the release of NPY and, subsequently, stimulation of feeding.
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000166:cytology / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D005947:Glucose / Q000378:metabolism / Q000502:physiology*; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000378:metabolism*; D009478:Neuropeptide Y / Q000378:metabolism*; D009994:Osmolar Concentration; D051381:Rats; D017207:Rats, Sprague-Dawley