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，也就是我们关注环境中特定元素的能力，学习，记忆和做出决定。参与这些认知功能的主要结构是前额叶皮层（PFC），位于我们眼睛后面的大脑前部。多巴胺和乙酰胆碱是这些神经化学物质中的两种，它们包含在PFC内的神经纤维中。研究表明，当需要注意力时，它们都发挥着积极的作用，例如，能够在人群中认出朋友。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。本研究的主题是确定这两种神经递质之间的相互作用以及PFC中与其他脑区通信以组织对外部刺激的反应的神经元。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，我们将在注意力任务期间测量它们在大鼠大脑中的浓度，以确定它们何时参与注意力过程以及大脑结构，以确定注意力的时间和神经元通路。此外，我们将测试的假设，PFC可以发挥其注意的作用，刺激乙酰胆碱神经元，这反过来又可以改变神经元的反应，某些刺激的第一步的视觉感知。因此，该学科研究视觉注意力的神经生物学基础，也就是说，一个刺激，你的朋友，如何在大脑中处理，而另一个，其他人，将被丢弃在存储在记忆中的各自意义的功能中。了解注意的神经生物学机制，意味着增加发现新的药物策略来缓解注意缺陷障碍的可能性，注意缺陷障碍损害人们的感知能力，导致学习，思维和最终退出社会活动的障碍。

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.