Cholinergic and dopaminergic interaction in the prefrontal cortex of rats

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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.