Body weight of rats following area postrema ablation: effect of early force-feeding.
This study examined the effect of intragastric force-feeding of a milk diet on body weights of rats with lesions of the area postrema/caudal medial nucleus of the solitary tract (AP/cmNTS). Force-feeding was conducted over the first 10 days after the ablation. Body weight was monitored both during and after force-feeding. Food intake was measured during all ad libitum feeding periods. During force-feeding, rats with AP/cmNTS lesions gained weight at the same rate as force-fed sham-lesioned rats or sham-lesioned rats that voluntarily ingested an equal amount of the milk. When returned to ad libitum feeding, lesioned rats that had been force-fed were not hypophagic and did not lose weight. Body weights of such rats remained above those of lesioned rats that were not force-fed and similar to those of nonlesioned rats throughout this study. Despite their normal weights, preliminary analysis indicated that body fat of the force-fed lesioned rats may have been reduced. These findings suggest that the effects of AP/cmNTS ablation are multiple and that reduction of body weight need not be the primary effect of such lesions.
Kenney
N J
NJ
Department of Psychology, University of Washington, Seattle 98195.
Kott
J N
JN
Tomoyasu
N
N
Bhatia
A J
AJ
Ruiz
A S
AS
McDowell
M M
MM
D000818:Animals; D001835:Body Weight; D002552:Cerebral Ventricles / Q000502:physiology*; D004734:Energy Metabolism; D005247:Feeding Behavior / Q000502:physiology; D005502:Food; D005518:Food Preferences; D008297:Male; D008526:Medulla Oblongata / Q000502:physiology*; D051381:Rats