Influence of the subfornical organ on meal-associated drinking in rats.
A lesion of the subfornical organ (SFO) may disrupt drinking after a meal of dry chow as it does drinking after intragastric administration of hypertonic saline. Food and water intakes of SFO-lesioned (SFOX) and sham-lesioned rats were measured during 90-min tests following various lengths of food deprivation. During the tests, all rats began eating before they began drinking. After 20-24 h of food deprivation, latency to begin drinking after eating had started was longer for SFOX than for sham-lesioned rats. Plasma osmolality was elevated by 2-3% in both lesion groups at 12 min, the latency for sham-lesioned rats to drink, but SFOX rats nevertheless continued eating and delayed drinking. Eating after shorter 4-h food deprivations and ad libitum feeding produced more variable drinking latencies and less consistent effects of SFO lesion. During 24 h of water deprivation, SFO lesion had no effect on the suppression of food intake and did not affect food or water intakes during the first 2 h of subsequent rehydration. These findings indicate that the SFO is involved in initiating water intake during eating and in determining drinking patterns and the amount of water ingested during a meal.
Starbuck
E M
EM
Department of Psychology, University of Washington, Seattle, Washington 98195, USA.
Fitts
D A
DA
D000818:Animals; D001769:Blood; D004326:Drinking / Q000502:physiology*; D004435:Eating; D004598:Electrosurgery; D005502:Food; D005508:Food Deprivation; D008297:Male; D009994:Osmolar Concentration; D051381:Rats; D020318:Rats, Long-Evans; D013356:Subfornical Organ / Q000502:physiology* / Q000601:surgery; D013997:Time Factors; D014868:Water Deprivation; D015431:Weight Loss