氟哌啶醇干扰决策过程中前扣带回神经元的放电活动

The Effects of Haloperidol on Neuronal Firing in Rats Anterior Cingulate Cortex During Cost-Benefit Decision-Making Tasks

运用在体多通道神经元放电同步记录技术,观察和记录大鼠在完成T-迷宫成本效益决策任务时前扣带回神经元放电和局部场电位的变化及氟哌啶醇对此的改变,在细胞水平上探讨前扣带回在决策中的作用以及多巴胺递质系统对决策的作用机制。结果显示,经过一段时间的训练,10只大鼠中有8只偏好高付出-高奖赏端,且在选择高付出-高奖赏端时的神经元放电频率要显著高于选择低付出-低奖赏端时的频率,同时局部场电位也呈现出事件相关性;腹腔注射多巴胺受体拮抗剂氟哌啶醇后,大鼠不再偏好高付出-高奖赏端,对该端的选择显著减少,而对低付出-低奖赏端的选择显著增加,且神经元的放电频率和局部场电位显著降低,神经元放电和局部场电位的特征性也消失。研究提示,前扣带回和多巴胺在努力相关决策任务中有着至关重要的作用。

There many studies have demonstrated that anterior cingulate cortex （ACC） and the level of dopamine （DA） in this brain area play a critical role in effort-based decision-making, a kind of cost-benefit decision-making. It has been found that haloperidol, a DA D2 receptor-antagonist, could disrupt the performance of rats in effort-based decision-making tasks. The present experimental study used on-line multi-channel neuronal recording technique to record both the neuronal firing frequency and local field potentials （LFPs） in ACC when rats were performing effort-based decision-making tasks. We further investigate the effects of haloperidol on performance of rats. All rats （10 Wistar rats） were surgically implanted with a 2×8 microelectrode array in ACC before they learned behavioral task. After 1 week of recovery, rats were introduced to T-maze for training periods. There were two choices in this task, rats could choose to get two food pellets at the end of one arm without any barrier （low cost-low reward, LCLR） or by climbing a barrier （high cost-high reward, HCHR） to get four pellets at the end of the other arm. After training for a period of time （about 2 weeks）, eight of ten rats preferred choosing HCHR. Electrophysiological research found five characteristic types of neuronal firing, and a great majority of ACC neurons showed significantly higher firing when to choose HCHR. Compared to control group （saline, 0.5ml, i.p）, injection of haloperidol （0.1mg/kg, i.p） significantly decreased the ratio of choosing HCHR, which made the characteristic firing of ACC neurons disappear and reduced LFPs of ACC. This indicates that haloperidol impaired the function of effort-based decision-making. No movement disorders or decreased appetite were observed through out experiments. In conclusion, the present study recorded activities of individual neurons in ACC when rats were performing decision-making tasks. We also studied the impact of haloperidol on the performance of rats. This study confirmed that ACC and actions of D2 receptor are very important in modulating effort-based decision-making.