Cholinergic and dopaminergic interaction in the prefrontal cortex of rats

大脑中神经化学物质的相互作用控制着我们的思想和认知能力，也就是我们对环境中特定元素的关注、学习、记忆和决策的能力。参与这些认知功能的主要结构是前额皮质（PFC），位于我们大脑的前部，就在我们眼睛后面。多巴胺和乙酰胆碱是其中的两种神经化学物质，由pfc内的神经元纤维所包含。研究表明，当需要注意能力时，它们都起着积极的作用，例如，能够在人群中认出一个朋友。乙酰胆碱能够增强PFC神经元的反应，多巴胺可以控制PFC中乙酰胆碱的数量。我的研究主题是确定这两种神经递质与PFC神经元之间的相互作用，PFC神经元与大脑其他区域交流，组织对外部刺激的反应。我们将标记含有这些神经化学物质的纤维，并通过显微镜观察它们之间的关系。在第二步中，我们将测量它们在注意力任务期间在大鼠大脑中的浓度，以确定它们何时参与到注意力过程中，以及在大脑的哪个结构中，以确定注意力的时间和神经元通路。此外，我们将验证PFC可以通过刺激乙酰胆碱神经元来发挥其注意作用的假设，乙酰胆碱神经元反过来可以改变神经元对视觉感知第一步中某些刺激的反应。因此，这门学科研究的是视觉注意的神经生物学基础，也就是说，一个刺激（你的朋友）是如何在大脑中被处理的，而另一个刺激（其他人）则会被丢弃，因为它们各自的重要性被储存在记忆中。注意缺陷障碍是一种损害人的感知能力，导致学习、思维障碍，最终退出社会活动的疾病。了解注意的神经生物学机制，意味着增加发现新的药物治疗策略的可能性。

The interaction of neurochemicals in the brain governs our mind and our cognitive abilities, that is our abilities to pay attention to specific elements of our environment, to learn, to memorize and to take decisions. The chief structure involved in these cognitive functions is the prefrontal cortex (PFC), located in the front of our brain just behind our eyes. Dopamine and acetylcholine are two of these neurochemicals, contained by the neuronal fibers within the PFC. It has been shown that both of them play an active role when the attention capacity is required, for being able to recognize a friend in a crowd for example. Acetylcholine is able to enhance the responses of PFC neurons and dopamine may control the quantity of acetylcholine in the PFC. The subject of my research is to determine the interaction in between these two neurotransmitters and the neurons from the PFC that communicate with other brain regions to organize a response to external stimulations. We will label the fibers containing these neurochemicals and visualize their relationship by microscopy.  In a second step we will measure their concentration in the brain of the rat during an attention task in order to determine when they are involved in the attentional processes and in which brain structure, to determine the timing and the neuronal pathways of attention. Moreover we will test the hypothesis that the PFC could exert its attentional role by stimulating acetylcholine neurons which in turn could change the neuronal response to certain stimuli in the first step of visual perception. Thus the subject studies the neurobiological basis of visual attention, i.e. how a stimulus, your friend, could be process in the brain, whereas another, other people, will be discarded in function of their respective significance stored in memory. Understanding the neurobiological mechanisms of attention, means to increase the probability to find new pharmacological strategies to alleviate attention deficit disorder, which impairs the perceptual abilities of people and results in disturbances in learning, thinking and finally withdrawal from social activity.