Phifer C B, Hall W G
Department of Psychology, Duke University, Durham, North Carolina 27706.
Am J Physiol. 1988 Aug;255(2 Pt 2):R191-9. doi: 10.1152/ajpregu.1988.255.2.R191.
Previous studies have indicated that the termination of intake in very young rat pups is controlled almost exclusively by the level of gastric fill; nutritive cues from diet have no effect on intake. In the present series of experiments, we investigated the ontogeny of postgastric nutritive controls of intake in rat pups ingesting independent of their dam. In 6-day-old pups, the level of gastric fill required to terminate ingestion was not affected by the presence or absence of post-gastric nutritive cues, but by 15 days of age a greater level of gastric fill was required to stop ingestion when postgastric cues were eliminated by a closed pyloric noose. This emergent post-gastric contribution to the inhibition of intake in 15-day-old pups does not depend on preexisting gastric fill signals, as sham-feeding pups (open gastric fistula) with nutrients in their intestines ingested less than pups without intestinal nutrients. These results provide evidence that postgastric controls of ingestive behavior mature during the postnatal period and just shortly before they are required at weaning.
先前的研究表明，幼龄大鼠幼崽摄食的终止几乎完全由胃内充盈程度控制；来自饮食的营养线索对摄食没有影响。在本系列实验中，我们研究了独立于母鼠进食的大鼠幼崽胃后营养性摄食控制的个体发生。在6日龄的幼崽中，终止摄食所需的胃内充盈程度不受胃后营养线索存在与否的影响，但到15日龄时，当通过闭合幽门套索消除胃后线索时，需要更高程度的胃内充盈才能停止摄食。这种15日龄幼崽胃后对摄食抑制的新出现的作用并不依赖于预先存在的胃内充盈信号，因为肠道内有营养物质的假饲幼崽（开放式胃瘘）比肠道内无营养物质的幼崽摄食量少。这些结果提供了证据，表明胃后摄食行为控制在出生后时期成熟，且就在断奶前不久就需要这种控制。
