Stickrod G, Kimble D P, Smotherman W P
Peptides. 1982 Nov-Dec;3(6):881-3. doi: 10.1016/0196-9781(82)90054-7.
Rat fetuses exposed to an odor stimulus and an aversive stimulus in utero showed an aversion to the odor when tested 16 days postnatally. Fetuses that also received 80 micrograms/kg Met-enkephalin showed a greater aversion to the odor stimulus than those subjects that did not receive the peptide. The difference between these groups was marginally significant. Control subjects did not show an aversion. But, subjects exposed to the odor and Met-enkephalin without the aversive stimulus, when tested, showed a significant preference for the odor over other control groups. These data show that associative learning in rat fetuses at 20 days of gestation may be enhanced by administration of Met-enkephalin.
在子宫内接触气味刺激和厌恶刺激的大鼠胎儿，在出生后16天进行测试时表现出对该气味的厌恶。同时接受80微克/千克甲硫氨酸脑啡肽的胎儿，比未接受该肽的受试者对气味刺激表现出更强的厌恶。这些组之间的差异边缘显著。对照组受试者没有表现出厌恶。但是，在测试时，接触气味和甲硫氨酸脑啡肽但没有厌恶刺激的受试者，比其他对照组对该气味表现出明显的偏好。这些数据表明，在妊娠20天时给大鼠胎儿施用甲硫氨酸脑啡肽可能会增强其联想学习能力。
