据5月29日的《科学》杂志报道说，研究人员已经发现，一种自然产生的叫做脑源性神经营养因子（或称BDNF）的蛋白是如何对脑部的某一特别区域发生作用以促进机体的药物寻求行为的，这一发现会为药物成瘾背后的生物学机制提供某些线索。
过去的研究已经显示，长期接触药品会增加脑中腹侧被盖区（VTA）中BDNF的水平，而这与机体多巴胺系统及“奖励”环路有关联。如今，Hector Vargas-Perez及其同僚应用小鼠来探索BDNF对VTA神经元的作用。他们报告说，BDNF直接参与VTA中的开关机制，它可以将身体的奖励环路从非多巴胺依赖系统转变为多巴胺依赖系统。 那些VTA神经元被注入BDNF的小鼠呈现了药物成瘾和戒断的行为特征。
研究人员说，BDNF将VTA中的某种特别的受体作用从抑制性转变成为兴奋性，从而导致了小鼠行为的改变。他们的发现与在其它动物及临床研究中所获得的结果相符，从而表明，BDNF对VTA的作用是药物成瘾的一个关键性的因子。（生物谷Bioon.com）
生物谷推荐原始出处：
Science May 28, 2009 DOI: 10.1126/science.1168501
Ventral Tegmental Area BDNF Induces an Opiate-Dependent–Like Reward State in Na?ve Rats
Hector Vargas-Perez 1*, Ryan Ting-A-Kee 2, Christine H. Walton 3, D. Micah Hansen 3, Rozita Razavi 1, Laura Clarke 2, Mary Rose Bufalino 2, David W. Allison 3, Scott C. Steffensen 3, Derek van der Kooy 4
1 Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada.
2 Institute of Medical Science, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada.
3 Department of Psychology, Brigham Young University, Provo, UT 84602, USA.
4 Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada.; Institute of Medical Science, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada.
The neural mechanisms underlying the transition from a drug-nondependent to a drug-dependent state remain elusive. Chronic exposure to drugs has been shown to increase BDNF levels in ventral tegmental area (VTA) neurons. BDNF infusions into the VTA potentiate several behavioral effects of drugs, including psychomotor sensitization and cue-induced drug seeking. We found that a single infusion of BDNF into the VTA promotes a shift from a dopamine-independent to a dopamine-dependent opiate reward system, identical to that seen when an opiate na?ve rat becomes dependent and withdrawn. This shift involves a switch in the GABA-A receptors of VTA GABAergic neurons, from inhibitory to excitatory signaling.
