Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA.
Neuroscience. 2012 Jan 3;200:91-8. doi: 10.1016/j.neuroscience.2011.10.012. Epub 2011 Oct 25.
Adolescents are more likely to experiment with and become addicted to drugs of abuse. A number of studies indicate that the developmental forebrain may be responsible for making adolescents vulnerable to the addictive properties of such drugs. The aim of this study was to first compare behavioral responses to novelty and cocaine between juvenile and adult rats and then compare levels of the immediate-early gene zif268 activation in several forebrain areas via in situ hybridization. We found that juveniles demonstrated higher locomotion scores and required a higher dose of cocaine than adults to establish a conditioned place preference. Additionally, at this higher dose, juvenile rats exhibited higher levels of zif268 mRNA in the prefrontal cortex compared with adults. A developmental effect for increased zif268 mRNA was also observed in the striatum and nucleus accumbens, but there was no interaction with the cocaine dose. These findings hold interesting implications for the study of the molecular mechanisms underlying juvenile drug addiction.
青少年更有可能尝试和沉迷于滥用药物。许多研究表明，发育中的前脑可能是导致青少年易受此类药物成瘾特性影响的原因。本研究的目的是首先比较幼年和成年大鼠对新奇事物和可卡因的行为反应，然后通过原位杂交比较几种前脑区域即刻早期基因zif268 的激活水平。我们发现，与成年大鼠相比，幼年大鼠表现出更高的运动评分，需要更高剂量的可卡因才能建立条件性位置偏好。此外，在这个更高的剂量下，幼年大鼠的前额叶皮层中的 zif268 mRNA 水平高于成年大鼠。纹状体和伏隔核中也观察到 zif268 mRNA 增加的发育效应，但与可卡因剂量没有相互作用。这些发现对研究青少年药物成瘾的分子机制具有重要意义。
