Spear L P, Frambes N A, Goodwin G
Department of Psychology, State University of New York, Binghamton 13902-6000.
Eur J Pharmacol. 1991 Oct 2;203(1):9-15. doi: 10.1016/0014-2999(91)90784-n.
Late preweanling (postnatal day 17-18; P17-18) and postweanling (P28-29) Sprague-Dawley rat pups were tested in the presence of both mash and liquid diets following s.c. administration of 0, 0.03, 0.06, 0.1 or 0.5 mg/kg of the 5-HT1A receptor agonist 8-hydroxy-2(di-n-propylamino)tetralin (8-OH-DPAT). Preweanling pups exhibited both a low dose stimulatory and high dose depressant effect of 8-OH-DPAT on mash-related ingestive behaviors, whereas postweanling rat pups were less sensitive to 8-OH-DPAT, exhibiting only an increase in mash ingestion within the dose range examined. In contrast, when neonatal (P3-4) rat pups were tested with milk across a dose range of 0.001-1.0 mg/kg 8-OH-DPAT, no increases in ingestion were seen, with lower doses in this range having no detectable effects and higher doses decreasing ingestion and mouthing. To the extent that low doses of 8-OH-DPAT increase feeding via preferential stimulation of 5-HT1A autoreceptors, these data suggest that neonates may lack functional 5-HT1A autoreceptors, with these receptors maturing by the late preweanling period.
在皮下注射0、0.03、0.06、0.1或0.5毫克/千克的5-羟色胺1A受体激动剂8-羟基-2（二正丙基氨基）四氢萘（8-OH-DPAT）后，对断奶前后期（出生后第17 - 18天；P17 - 18）和断奶后（P28 - 29）的斯普拉格-道利幼鼠在同时存在糊状饲料和液体饲料的情况下进行测试。断奶前幼鼠表现出8-OH-DPAT对与糊状饲料相关的摄食行为具有低剂量刺激和高剂量抑制作用，而断奶后幼鼠对8-OH-DPAT的敏感性较低，在所检测的剂量范围内仅表现出糊状饲料摄入量增加。相比之下，当对新生（P3 - 4）幼鼠在0.001 - 1.0毫克/千克8-OH-DPAT剂量范围内用牛奶进行测试时，未观察到摄入量增加，该范围内较低剂量无可检测到的影响，较高剂量则减少摄入量和吸吮行为。就低剂量的8-OH-DPAT通过优先刺激5-羟色胺1A自身受体来增加摄食而言，这些数据表明新生幼鼠可能缺乏功能性5-羟色胺1A自身受体，这些受体在断奶前后期成熟。
