D2 dopamine modulation of corticoaccumbens synaptic responses changes during adolescence
D2 dopamine modulation of corticoaccumbens synaptic responses changes during adolescence
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DOI：
10.1111/j.1460-9568.2008.06107.x
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发表时间：
2008-03-01
影响因子：
3.4
通讯作者：
O'Donnell, Patricio
中科院分区：
文献类型：
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作者：
Benoit-Marand, Marianne;O'Donnell, Patricio
来自腹侧被盖区(VTA)的多巴胺能传入调节伏核(NA)的信息处理，NA是大脑中对动机和奖励机制至关重要的区域。在幼年大鼠的NA中棘神经元(MSN)中，D-2激动剂可降低皮质伏隔核突触反应的幅度。由于一些与多巴胺相关的功能在青春期发生变化，我们用从成年和青春期前大鼠脑片上获得的全细胞记录来评估皮质输入的D-2调制。D-2激动剂奎比罗(5 MU M)可降低电刺激青春期前大鼠脑片NA MSN的突触反应。然而，在成年大鼠的脑片上，奎比罗增加了诱发的突触反应的幅度和自发突触事件的频率。这些作用可被GABA-A拮抗剂印防己毒素(50MU)阻断，显示D-2介导的减弱。这些结果表明，D-2受体对幼年和成年大鼠NA神经元的调节不同，这是由于在青春期皮质伏隔反应中出现了D-2促进的GABA成分。
Dopaminergic afferents from the ventral tegmental area (VTA) modulate information processing in the nucleus accumbens (NA), a brain region critical for motivation and reward mechanisms. In NA medium spiny neurons (MSNs) from young rats, D-2 agonists have been shown to decrease the amplitude of corticoaccumbens synaptic responses. As several dopamine-related functions change during adolescence, we assessed the D-2 modulation of cortical inputs with whole-cell recordings in slices obtained from adult and preadolescent rats. The D-2 agonist quinpirole (5 mu M) decreased synaptic response of NA MSNs to electrical cortical stimulation in slices from preadolescent rats. In slices from adult rats, however, quinpirole increased both the amplitude of evoked synaptic responses and the frequency of spontaneous synaptic events. These effects were blocked by the GABA-A antagonist picrotoxin (50 mu M), revealing a D-2-mediated decrease These results suggest that D-2 receptors modulate NA neurons differently in young and adult rats, due to the emergence of a D-2-facilitated GABA component in corticoaccumbens responses during adolescence.