Matsuzaka Yoshiya, Tanji Jun, Mushiake Hajime
Department of Physiology, Graduate School of Medicine, and
Brain Science Center, Tohoku University, Sendai 980-8575, Japan.
J Neurosci. 2016 Jun 1;36(22):5974-87. doi: 10.1523/JNEUROSCI.4572-15.2016.
To expedite the selection of action under a structured behavioral context, we develop an expedient to promote its efficiency: tactics for action selection. Setting up a behavioral condition for subhuman primates (Macaca fuscata) that induced the development of a behavioral tactics, we explored neuronal representation of tactics in the medial frontal cortex. Here we show that neurons in the posterior medial prefrontal cortex, but not much in the medial premotor cortex, exhibit activity representing the behavioral tactics, in advance of action-selective activity. Such activity appeared during behavioral epochs of its retrieval from instruction cues, maintenance in short-term memory, and its implementation for the achievement of action selection. At a population level, posterior medial prefrontal cortex neurons take part in transforming the tactics information into the information representing action selection. The tactics representation revealed an aspect of neural mechanisms for an adaptive behavioral control, taking place in the medial prefrontal cortex.
We studied behavioral significance of neuronal activity in the posterior medial prefrontal cortex (pmPFC) and found the representation of behavioral tactics defined as specific and efficient ways to achieve objectives of actions. Neuronal activity appeared during behavioral epochs of its retrieval from instruction cues, maintenance in short-term memory, and its use preceding the achievement of action selection. We found further that pmPFC neurons take part in transforming the tactics information into the information representing action selection. A majority of individual neurons was recruited during a limited period in each behavioral epoch, constituting, as a whole, a temporal cascade of activity. Such dynamics found in behavioral-tactics specific activity characterize the participation of pmPFC neurons in executive control of purposeful behavior.
为了在结构化行为背景下加快行动选择,我们开发了一种促进其效率的方法:行动选择策略。我们为猕猴(食蟹猴)设定了一种行为条件,诱导其发展出一种行为策略,并探索了内侧前额叶皮质中策略的神经元表征。我们发现,后内侧前额叶皮质中的神经元,但内侧运动前皮质中的神经元则不然,在行动选择活动之前就表现出代表行为策略的活动。这种活动出现在从指令线索中检索策略、在短期记忆中维持策略以及为实现行动选择而执行策略的行为阶段。在群体水平上,后内侧前额叶皮质神经元参与将策略信息转化为代表行动选择的信息。策略表征揭示了内侧前额叶皮质中发生的适应性行为控制的神经机制的一个方面。
我们研究了后内侧前额叶皮质(pmPFC)中神经元活动的行为意义,发现了行为策略的表征,行为策略被定义为实现行动目标的特定且有效的方式。神经元活动出现在从指令线索中检索策略、在短期记忆中维持策略以及在实现行动选择之前使用策略的行为阶段。我们进一步发现,pmPFC神经元参与将策略信息转化为代表行动选择的信息。在每个行为阶段的有限时间内,大多数单个神经元被激活,整体构成了一个时间上的活动级联。在行为策略特定活动中发现的这种动态特征表明pmPFC神经元参与了有目的行为的执行控制。