Carelli Regina M, Williams Jefferson G, Hollander Jonathan A
Department of Psychology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3270, USA.
J Neurosci. 2003 Sep 10;23(23):8204-11. doi: 10.1523/JNEUROSCI.23-23-08204.2003.
Electrophysiological recording procedures were used to examine basolateral amygdala (BLA) cell firing during cocaine self-administration and relative to response-independent presentations of cocaine-associated stimuli. Of 72 neurons (n = 10 rats), 31 cells (43%) were classified as phasically active, exhibiting one of three types of patterned discharges relative to the drug-reinforced response, similar to that previously described for nucleus accumbens (Acb) neurons (Carelli, 2002). Briefly, neurons exhibited increased firing rates within seconds preceding the response [termed preresponse (PR)], increased activity within seconds after the response [termed reinforcement excitation (RFe)] or an inhibition in cell firing before and/or after the response for intravenous cocaine [termed reinforcement inhibition (RFi)]. To examine the responsiveness of these same neurons to cocaine-associated stimuli, the stimulus "probe" procedure was used. Specifically, probe trials (18-20) were presented in which the audiovisual (tone-house light) stimulus associated with intravenous cocaine delivery during self-administration was randomly presented by the computer, interspersed between reinforced lever press responses. Neurons classified as type PR or type RFi were not activated by the stimulus. In contrast, neurons that exhibited increased firing immediately after the response (type RFe neurons) were significantly activated by the audiovisual cue. These findings are discussed with respect to the role of the BLA in cocaine addiction as well as previous studies characterizing Acb cell firing during cocaine self-administration.
采用电生理记录程序，在可卡因自我给药期间以及相对于可卡因相关刺激的非反应依赖性呈现过程中，检查基底外侧杏仁核（BLA）细胞的放电情况。在72个神经元（n = 10只大鼠）中，31个细胞（43%）被归类为相位活跃型，相对于药物强化反应表现出三种模式放电中的一种，类似于先前描述的伏隔核（Acb）神经元（Carelli，2002）。简而言之，神经元在反应前几秒内放电率增加[称为反应前（PR）]，在反应后几秒内活动增加[称为强化兴奋（RFe）]，或者在静脉注射可卡因的反应前和/或后细胞放电受到抑制[称为强化抑制（RFi）]。为了检查这些相同神经元对可卡因相关刺激的反应性，使用了刺激“探针”程序。具体而言，进行了（18 - 20次）探针试验，其中与自我给药期间静脉注射可卡因相关的视听（音调 - 室内灯光）刺激由计算机随机呈现，穿插在强化的杠杆按压反应之间。归类为PR型或RFi型的神经元未被该刺激激活。相反，在反应后立即表现出放电增加的神经元（RFe型神经元）被视听线索显著激活。结合BLA在可卡因成瘾中的作用以及先前关于可卡因自我给药期间Acb细胞放电特征的研究，对这些发现进行了讨论。
