FIRING PATTERNS OF NUCLEUS-ACCUMBENS NEURONS DURING COCAINE SELF-ADMINISTRATION IN RATS
FIRING PATTERNS OF NUCLEUS-ACCUMBENS NEURONS DURING COCAINE SELF-ADMINISTRATION IN RATS
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DOI：
10.1016/0006-8993(93)90557-4
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发表时间：
1993-10-29
期刊：
影响因子：
2.9
通讯作者：
DEADWYLER, SA
中科院分区：
文献类型：
--
作者：
CARELLI, RM;KING, VC;DEADWYLER, SA
记录了训练大鼠通过响应性静脉药物输注自我给药可卡因的延髓核（NA）神经元的放电模式。在由16-30次给药事件组成的试验期间，从双侧插入NA和/或腹侧纹状体（NA-VS）的永久植入多个电极阵列（8根微导线）中获得记录，这些电极阵列在动物中表现出稳定的反应（输注间隔，INT）。电子隔离和鉴定的NA-VS神经元表现出不同的模式，阶段性增加，在发射相对于发生的加强杠杆压力。然而，在不同的动物身上，人们反复遇到了两种特殊的放电模式。在一种类型中，观察到响应条件药物递送后的放电显著增加。第二个放电模式显示了两个不同的时间上分离的短暂放电峰（爆发），一个是在响应开始之前立即出现的，另一个是在药物输送开始后200 ms内开始的短暂放电。发现放电峰之间的时间可通过改变药物递送的响应/奖励（FR）比来修改。第三个发现是，自我给药反应的相关性不仅仅是药物输注的结果，因为（1）在同一疗程期间非偶然性输注药物时，未观察到阶段性放电增加，（2）在疗程内模式的出现经常延迟，直到药物自我给药行为稳定在常规INT之后。研究结果进行了讨论的意义NA-VS神经元放电相关的可卡因自我管理的启动和维护。
The firing patterns of neurons in the nucleus accumbens (NA) were recorded in rats trained to self-administer cocaine via response contingent intravenous drug infusions. Recordings were obtained from permanently implanted multiple electrode arrays (8 microwires) inserted bilaterally into the NA and/or ventral striatum (NA-VS) in animals exhibiting stable responding (inter-infusion intervals, INT) during test sessions consisting of 16-30 drug delivery episodes. Electronically isolated and identified NA-VS neurons showed distinct patterns of phasic increases in firing relative to the occurrence of the reinforced lever press. Two particular firing patterns, however, were repeatedly encountered in different animals. In one type, a marked increase was observed in discharge following response contingent drug delivery. A second firing pattern showed two distinct temporally separated brief firing peaks (bursts), one immediately prior to the initiation of responding, and the other a brief discharge commencing within 200 ms after the initiation of drug delivery. The time between firing peaks was found to be modifiable by changing the response/reward (FR) ratio for drug delivery. A third finding was that the correlates of the self-administration response were not solely the result of drug infusion since, (1) phasic firing increases were not observed when the drug was delivered non-contingently during the same session and, (2) the emergence of patterns was frequently delayed within the session until after drug self-administration behavior stabilized at regular INTs. The findings are discussed in terms of the significance of NA-VS neuron firing correlates for the initiation and maintenance of cocaine self-administration.