Oral somatosensory factors in dietary self-selection after food deprivation and supplementation.
In order to study the role of oral somatosensory input in the ability of rats to adjust protein selection to changing metabolic conditions, trigeminally deafferented animals were subjected to nutritional stresses while being allowed to balance protein and carbohydrate intake from two separate dietary fractions. Partially trigeminally deafferented rats that had recovered a normal protein ratio (protein/total intake) underwent total food deprivation (Experiment 1) or intragastric (IG) supplementation of protein or carbohydrate suspensions (Experiment 2). In response to deprivation, control rats increased protein intake above ad-lib levels, but not carbohydrate intake. In response to IG supplementation, they decreased protein intake disproportionately more than carbohydrate intake when the fluid consisted of protein and vice versa when the fluid consisted of carbohydrate. The recovered deafferented rats showed no selective increase in protein intake after deprivation and no differential compensation to nutrient supplementation. This suggests that recovery of the protein ratio after partial trigeminal deafferentation is incomplete and that the compensatory mechanisms used cannot fully replace the function of trigeminal somatosensory input. The possible role of other orosensory and of postingestional factors for recovery is discussed.
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D002149:Energy Intake; D005508:Food Deprivation; D005518:Food Preferences; D006815:Hunger / Q000502:physiology*; D008297:Male; D009055:Mouth / Q000294:innervation*; D051381:Rats; D011919:Rats, Inbred Strains; D011984:Sensory Receptor Cells / Q000502:physiology*; D014276:Trigeminal Nerve / Q000502:physiology*
D004040:Dietary Carbohydrates; D004044:Dietary Proteins