Differences between accumbens core and shell neurons exhibiting phasic firing patterns related to drug-seeking behavior during a discriminative-stimulus task
Differences between accumbens core and shell neurons exhibiting phasic firing patterns related to drug-seeking behavior during a discriminative-stimulus task
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DOI：
10.1152/jn.00268.2004
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发表时间：
2004-09-01
影响因子：
2.5
通讯作者：
West, MO
中科院分区：
文献类型：
--
作者：
Ghitza, UE;Fabbricatore, AT;West, MO
滥用药物的成瘾效应依赖于支配中脑皮质边缘多巴胺系统（NAcc）。为了检查不同的NAcc亚区（核心和内侧壳）是否表现出神经元的差异分布，这些神经元显示出与药物寻求行为相关的阶段性放电模式，训练大鼠自我施用可卡因，并记录单个NAcc神经元的活性。在歧视刺激（S-D）音的存在下，一个单一的杠杆按下产生的可卡因（0.35毫克/公斤）的静脉输注，终止的音调，并开始一个intertone间隔范围从3到6分钟。杠杆按下在此intertone间隔没有编程的后果。除了评估与可卡因加强按压相关的神经元放电模式外，我们还评估了与未加强杠杆按压相关的放电模式，以允许解释除仪器反应以外的因素（如音调关闭和泵信号药物输注的开始）。核心神经元表现出更大的变化，在发射比内侧壳神经元在前几秒钟的加强和未加强的杠杆压力响应，并在几秒钟后的未加强的响应。核心和内侧壳神经元表现出类似的变化，在几秒钟后，可卡因加强新闻。差异分布的神经元表现出阶段性的变化，在发射前的杠杆按下表明，在与执行条件药物寻求反应的过程中，核心神经元的生理活动可能发挥更大的作用比内侧壳神经元。
The habit-forming effects of abused drugs depend on the mesocorticolimbic dopamine system innervating the nucleus accumbens (NAcc). To examine whether different NAcc subterritories ( core and medial shell) exhibit a differential distribution of neurons showing phasic firing patterns correlated with drug-seeking behavior, rats were trained to self-administer cocaine, and activity of single NAcc neurons was recorded. In the presence of a discriminative-stimulus (S-D) tone, a single lever press produced an intravenous infusion of cocaine (0.35 mg/kg), terminated the tone, and started an intertone interval ranging from 3 to 6 min. Lever presses during this intertone interval had no programmed consequences. In addition to evaluating neuronal firing patterns associated with cocaine-reinforced presses, we also evaluated firing patterns associated with unreinforced lever presses to allow interpretation of firing free of factors other than the instrumental response ( such as tone-off and onset of the pump signaling drug infusion). Core neurons exhibited a greater change in firing than medial shell neurons both in the seconds preceding the reinforced and unreinforced lever press response and in the seconds following the unreinforced response. Core and medial shell neurons exhibited similar changes in firing during the seconds following the cocaine-reinforced press. The differential distribution of neurons exhibiting phasic changes in firing preceding the lever press suggests that the physiological activity of core neurons may play a greater role than that of medial shell neurons in processes related to the execution of conditioned drug-seeking responses.