據(jù)5月29日的《科學(xué)》雜志報(bào)道說,，研究人員已經(jīng)發(fā)現(xiàn)，一種自然產(chǎn)生的叫做腦源性神經(jīng)營養(yǎng)因子（或稱BDNF）的蛋白是如何對腦部的某一特別區(qū)域發(fā)生作用以促進(jìn)機(jī)體的藥物尋求行為的，這一發(fā)現(xiàn)會為藥物成癮背后的生物學(xué)機(jī)制提供某些線索,。
過去的研究已經(jīng)顯示,，長期接觸藥品會增加腦中腹側(cè)被蓋區(qū)（VTA）中BDNF的水平，而這與機(jī)體多巴胺系統(tǒng)及“獎(jiǎng)勵(lì)”環(huán)路有關(guān)聯(lián),。如今,，Hector Vargas-Perez及其同僚應(yīng)用小鼠來探索BDNF對VTA神經(jīng)元的作用。他們報(bào)告說,，BDNF直接參與VTA中的開關(guān)機(jī)制,，它可以將身體的獎(jiǎng)勵(lì)環(huán)路從非多巴胺依賴系統(tǒng)轉(zhuǎn)變?yōu)槎喟桶芬蕾囅到y(tǒng)。 那些VTA神經(jīng)元被注入BDNF的小鼠呈現(xiàn)了藥物成癮和戒斷的行為特征,。
研究人員說,，BDNF將VTA中的某種特別的受體作用從抑制性轉(zhuǎn)變成為興奮性，從而導(dǎo)致了小鼠行為的改變,。他們的發(fā)現(xiàn)與在其它動物及臨床研究中所獲得的結(jié)果相符,，從而表明，BDNF對VTA的作用是藥物成癮的一個(gè)關(guān)鍵性的因子,。（生物谷Bioon.com）
生物谷推薦原始出處：
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to a dopamine-dependent opiate reward system, identical to that seen when an opiate na?ve rat becomes dependent and withdrawn.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.
