Nucleus accumbens injections of the mGluR2/3 agonist LY379268 increase cue-induced sucrose seeking following adult, but not adolescent sucrose self-administration.
Nucleus accumbens injections of the mGluR2/3 agonist LY379268 increase cue-induced sucrose seeking following adult, but not adolescent sucrose self-administration.
复制标题
伏核注射 mGluR2/3 激动剂 LY379268 会增加成人自行施用蔗糖后提示诱导的蔗糖寻求，但不会增加青少年自行施用蔗糖。
DOI：
10.1016/j.neuroscience.2015.07.077
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发表时间：
2015
期刊：
影响因子：
3.3
通讯作者：
Counotte,DS
中科院分区：
文献类型：
--
作者：
Myal,S;O'Donnell,P;Counotte,DS
Adolescence is often portrayed as a period of enhanced sensitivity to reward, with long-lasting neurobiological changes upon reward exposure. However, we previously found that time-dependent increases in cue-induced sucrose seeking were more pronounced in rats trained to self-administer sucrose as adults than as adolescents. In addition, adult, but not adolescent sucrose self-administration led to a decreased α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/N-Methyl-D-aspartate (AMPA/NMDA) ratio in the nucleus accumbens core, suggesting that long-lasting changes in glutamatergic transmission may affect adult processing of natural rewards. Here we tested whether altering glutamatergic transmission in the nucleus accumbens core via local injection of an mGluR2/3 agonist and antagonist affects cue-induced sucrose seeking following abstinence and whether this is different in the two age groups.Rats began oral sucrose self-administration training (10 days) on postnatal day (P) 35 (adolescents) or P70 (adults). Following 21 days of abstinence, rats received microinjections of the mGluR2/3 agonist LY379268 (0.3 or 1.0 μg/side) or vehicle into the nucleus accumbens core, and 15 min later cue-induced sucrose seeking was assessed. An additional group of rats trained as adults received nucleus accumbens core microinjections of the mGluR2/3 antagonist (RS)-α-Methyl-4-phosphonophenylglycine (MPPG) (0.12 or 0.5 μg/side).Confirming our previous results, adult rats earned more sucrose reinforcers, while sucrose intake per body weight was similar across ages. On abstinence day 22, local injection of the mGluR2/3 agonist LY379268 increased cue-induced sucrose seeking only in adult rats, and had no effect in adolescents. Local injections of the mGluR2/3 antagonist MPPG had no effect on sucrose seeking in adult rats. These data suggest an important developmental difference in the neural substrates of natural reward, specifically a difference in glutamatergic transmission in the accumbens in cue-induced responding for sucrose between adolescent and adult rats.
