Barron S, Kaiser D H, Hansen L S
University of Kentucky, Lexington 40506.
Neurotoxicol Teratol. 1994 Jul-Aug;16(4):401-9. doi: 10.1016/0892-0362(94)90029-9.
This study examined the effects of neonatal cocaine exposure on running wheel activity and subsequent responsivity to cocaine using a rodent model. Subjects were artificially reared from postnatal (PND) days 4-10 via an intragastric cannula. The four treatment groups included two cocaine doses (20 mg/kg/day and 40 mg/kg/day), an artificially reared control and a normally reared suckled control. Subjects were tested at either PND 21 through PND 24 (Experiment 1) or PND 60 through PND 70 (Experiment 2) for 2 consecutive days. Testing consisted of a 30-min habituation period followed by injection of either saline (Day 1) or cocaine (Day 2) and an additional 60-min test session. Neonatal treatment had little effect on baseline activity or activity following saline injection at either age. All subjects showed an activation with cocaine injections, however, the activation was more pronounced in juveniles. Again, neonatal treatment did not interact with response to cocaine. These findings suggest that neonatal cocaine exposure does not alter activity or long-term responsivity to 20 mg/kg cocaine as measured in the running wheel apparatus.
本研究使用啮齿动物模型，研究了新生期接触可卡因对转轮活动以及随后对可卡因反应性的影响。实验对象在出生后第4天至第10天通过胃内插管进行人工饲养。四个治疗组包括两种可卡因剂量（20毫克/千克/天和40毫克/千克/天）、一个人工饲养对照组和一个正常饲养的哺乳对照组。实验对象在出生后第21天至第24天（实验1）或出生后第60天至第70天（实验2）连续测试2天。测试包括30分钟的适应期，随后注射生理盐水（第1天）或可卡因（第2天），并进行额外60分钟的测试时段。新生期治疗对两个年龄段的基础活动或注射生理盐水后的活动几乎没有影响。然而，所有实验对象注射可卡因后均表现出活动增加，不过，这种活动增加在幼年实验对象中更为明显。同样，新生期治疗与对可卡因的反应没有相互作用。这些研究结果表明，如在转轮装置中所测量的，新生期接触可卡因不会改变活动或对20毫克/千克可卡因的长期反应性。
