Gastric preloads of corn oil and mineral oil produce different patterns of increases of c-Fos-like immunoreacitve cells in the brain of 9-12 day-old rats.
Equivolumetric gastric preloads of corn oil and mineral oil administered to rats on postnatal day 12 (P12) inhibited intake equally during a 30-min test of independent ingestion (II), but preloads of corn oil inhibited intake significantly more than preloads of mineral oil on P15 and P18 [Weller, A., Gispan, I.H., Armony-Sivan, R., Ritter, R.C., Smith, G.P., 1997. Preloads of corn oil inhibit independent ingestion on postnatal day 15 in rats. Physiol. Behav. 62, 871-874]. It is possible that the equivalent inhibition of intake by the oil preloads on P12 resulted from the failure of the preabsorptive sensory properties of the preloads to be discriminated by peripheral or central sensory mechanisms. To investigate this possibility, we administered equivolumetric gastric preloads of 25% corn oil and 25% mineral oil to pups on P9-12 and counted the number of c-Fos-like immunoreactive (CFLI) cells in central sites that are activated by food intake and postingestive preabsortive mechanisms in adult rats and in pups on P10-11. The major result was that preloads of 25% corn oil and 25% mineral oil that produced equivalent inhibition of II intake produced differential increases of CFLI cells in the forebrain and hindbrain. Specifically, preloads of corn oil increased the number of CFLI cells in the caudal Nucleus Tractus Solitarius significantly more than preloads of mineral oil. Furthermore, preloads of corn oil increased the number of CFLI cells in the Paraventricular and Supraoptic nuclei, but preloads of mineral oil did not. This differential pattern of increases of CFLI cells is evidence that the brain discriminates the preabsorptive sensory properties of preloads of corn oil and mineral oil on P9-12.
Blumberg
Sara
S
Developmental Psychobiology Laboratory, Department of Psychology and the Gonda (Goldschmeid) Brain Research Center, Bar Ilan University, Ramat Gan 52900, Israel, and Department of Psychiatry, New York-Presbyterian Hospital, White Plains, NY 10605, USA.
Schroeder
Mariana
M
Malkesman
Oz
O
Torregrossa
Ann Marie
AM
Smith
Gerard P
GP
Weller
Aron
A
D000375:Aging / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000187:drug effects / Q000254:growth & development*; D002766:Cholecystokinin / Q000378:metabolism; D003314:Corn Oil / Q000494:pharmacology*; D005227:Fatty Acids / Q000378:metabolism / Q000494:pharmacology; D005260:Female; D041981:Gastrointestinal Tract / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D007031:Hypothalamus / Q000187:drug effects / Q000254:growth & development; D007150:Immunohistochemistry; D008297:Male; D008899:Mineral Oil / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D012528:Satiety Response / Q000187:drug effects / Q000502:physiology*; D011984:Sensory Receptor Cells / Q000187:drug effects / Q000254:growth & development; D017552:Solitary Nucleus / Q000187:drug effects / Q000254:growth & development; D014630:Vagus Nerve / Q000187:drug effects / Q000254:growth & development; D017833:Visceral Afferents / Q000187:drug effects / Q000254:growth & development*
D005227:Fatty Acids; D016760:Proto-Oncogene Proteins c-fos; D003314:Corn Oil; D008899:Mineral Oil; D002766:Cholecystokinin