Ding Tong-Hao, Hu Yu-Ying, Li Jia-Wen, Sun Chong, Ma Chao-Lin
Institute of Biomedical Innovation, Nanchang University, Nanchang 330031, China.
School of Life Science, Nanchang University, Nanchang 330031, China.
Cereb Cortex. 2024 Dec 3;34(12). doi: 10.1093/cercor/bhae476.
Value-based decision-making involves weighing costs and benefits. The activity of the medial prefrontal cortex reflects cost-benefit assessments, and the mediodorsal thalamus, reciprocally connected with the medial prefrontal cortex, has increasingly been recognized as an active partner in decision-making. However, the specific role of the interaction between the mediodorsal thalamus and the medial prefrontal cortex in regulating the neuronal activity underlying how costs and benefits influence decision-making remains largely unexplored. We investigated this by training the rats to perform a self-determined decision-making task, where longer nose poke durations resulted in correspondingly larger rewards. Our results showed that the inactivation of either the medial prefrontal cortex or the mediodorsal thalamus significantly impaired rat to invest more nose poke duration for larger rewards. Moreover, optogenetic stimulation of the mediodorsal thalamus-medial prefrontal cortex pathway enhanced rats' motivation for larger rewards, whereas inhibition of this pathway resulted in decreased motivation. Notably, we identified a specific population of neurons in the medial prefrontal cortex that exhibited firing patterns correlated with motivation, and these neurons were modulated by the mediodorsal thalamus-medial prefrontal cortex projection. These findings suggest that the motivation during decision-making is encoded primarily by activity of particular neurons in the medial prefrontal cortex and indicate the crucial role of the mediodorsal thalamus-medial prefrontal cortex pathway in maintaining motivation.
基于价值的决策涉及权衡成本和收益。内侧前额叶皮层的活动反映了成本效益评估，而与内侧前额叶皮层相互连接的背内侧丘脑，越来越被认为是决策过程中的一个积极参与者。然而，背内侧丘脑与内侧前额叶皮层之间的相互作用在调节成本和收益如何影响决策的潜在神经元活动方面的具体作用，在很大程度上仍未得到探索。我们通过训练大鼠执行一项自我决定的决策任务来对此进行研究，在该任务中，更长时间的鼻触持续时间会带来相应更大的奖励。我们的结果表明，内侧前额叶皮层或背内侧丘脑的失活显著损害了大鼠为获得更大奖励而投入更多鼻触持续时间的能力。此外，对背内侧丘脑 - 内侧前额叶皮层通路进行光遗传学刺激增强了大鼠对更大奖励的动机，而抑制该通路则导致动机下降。值得注意的是，我们在内侧前额叶皮层中鉴定出了一群特定的神经元，它们表现出与动机相关的放电模式，并且这些神经元受到背内侧丘脑 - 内侧前额叶皮层投射的调节。这些发现表明，决策过程中的动机主要由内侧前额叶皮层中特定神经元的活动编码，并表明背内侧丘脑 - 内侧前额叶皮层通路在维持动机方面的关键作用。
