Neigh G N, Arnold H M, Rabenstein R L, Sarter M, Bruno J P
Department of Psychology, 31 Townshend Hall, The Ohio State University, 43210, Columbus, OH, USA.
Neuroscience. 2004;123(3):635-45. doi: 10.1016/j.neuroscience.2003.10.006.
In vivo microdialysis was used to determine the necessity of neuronal activity in the nucleus accumbens (NAC) for task-induced increases in cortical acetylcholine (ACh) efflux. Rats were trained in a behavioral task in which they were required to perform a defined number of licks of a citric acid solution in order to gain access to a palatable, cheese-flavored food. Upon reaching a consistent level of performance, rats were implanted with microdialysis cannula in the medial prefrontal cortex (mPFC) and either the ipsilateral shell of the NAC or in the dorsal striatum (STR; control site). Dialysis samples from the mPFC were analyzed for ACh concentrations and samples from the NAC were analyzed for dopamine (DA) concentrations. Performance in the task was associated with increases in both ACh efflux in the cortex (150-200%) and DA efflux in the NAC (50-75%). These increases were blocked by administration of tetrodotoxin (TTX; 1.0 microM) via reverse dialysis into the NAC. Administration of TTX into the dorsal STR control site was ineffective in blocking performance-associated increases in cortical ACh. The D2 antagonist sulpiride (10 or 100 microM) administered into the NAC via reverse dialysis was ineffective in blocking increases in cortical ACh efflux. The present data reveal that neuronal activity in the NAC is necessary for behaviorally induced increases in cortical ACh efflux and that this activation does not require increases in D2 receptor activity.
采用体内微透析技术来确定伏隔核（NAC）中神经元活动对于任务诱导的皮质乙酰胆碱（ACh）外流增加的必要性。对大鼠进行一项行为任务训练，要求它们舔一定次数的柠檬酸溶液，以便获取美味的奶酪味食物。在达到稳定的表现水平后，将微透析套管植入内侧前额叶皮质（mPFC）以及NAC的同侧壳区或背侧纹状体（STR；对照部位）。分析来自mPFC的透析样本中的ACh浓度，分析来自NAC的样本中的多巴胺（DA）浓度。任务表现与皮质中ACh外流增加（150 - 200%）以及NAC中DA外流增加（50 - 75%）相关。通过反向透析向NAC注射河豚毒素（TTX；1.0微摩尔）可阻断这些增加。向背侧STR对照部位注射TTX对阻断与任务表现相关的皮质ACh增加无效。通过反向透析向NAC注射D2拮抗剂舒必利（10或100微摩尔）对阻断皮质ACh外流增加无效。目前的数据表明，NAC中的神经元活动对于行为诱导的皮质ACh外流增加是必要的，并且这种激活不需要D2受体活性增加。
