Acetylcholine role in the reward system and individual approach style.

早在巴甫洛夫最初的条件反射实验中，研究人员就注意到一些动物试图通过鸣叫蜂鸣器来获取食物。在实验中，狗听到蜂鸣器的声音就会分泌唾液，而蜂鸣器的声音与食物即将到来有关。在其他物种中也可以观察到同样的行为。在老鼠身上，在动物接受食物之前，给它们一个没有功能的杠杆，会导致一些动物按下杠杆，这种行为被称为“信号追踪”。其他动物会选择食物分配（目标跟踪），或者在这两种行为之间交替进行。这些个体的行为方式与其他表型相关——标记追踪动物的注意力控制能力差，有成瘾倾向，药物复发的可能性更大。在包括人类在内的其他物种中也可以观察到这些个体的行为方式，在这些物种中，信号追踪与肥胖有关。参与信号追踪的动物在神经系统上存在一些差异，尤其是它们的多巴胺能奖励系统（D2和D3受体，DAT）。虽然乙酰胆碱是一种功能与注意力有关的神经递质，但这种神经递质对多巴胺能系统有一定的控制作用，可能参与了信号跟踪行为。只有少数研究考察了乙酰胆碱在个人风格行为中的作用。由于已知的信号追踪大鼠表现出依赖于乙酰胆碱的注意力缺陷，我们怀疑乙酰胆碱系统的控制较弱。乙酰胆碱在很大程度上被忽视了；它的研究是一个基本的兴趣，因为它被认为是控制奖励因素。***我的创新研究项目旨在更好地理解乙酰胆碱在奖励评估中的作用和方法风格的个体差异。为了确定乙酰胆碱在个人方法风格中的作用，提出了三个具体目标。我们将通过损伤大脑的3个不同的乙酰胆碱区域（自上而下的注意力，自下而上的注意力和奖励系统）来确定胆碱能系统的不同部分在个体方法风格中的作用。2-我们将根据个体方法风格评估电生理（ERP）差异。3-我们将量化在目标1中提到的三个区域中，符号跟踪器和目标跟踪器动物的神经解剖学差异。总的来说，这些发现将提供关于个体方法风格起源的新知识，尤其重要的是，因为这些动物也表现出注意力缺陷，易受药物依赖和更容易复发。乙酰胆碱在个体接近方式中的作用为更好地理解成瘾、注意力控制及其合并症提供了新的视角

As early as Pavlov's original conditioning experiments –in which dogs began to salivate to the sound of a buzzer that had been associated with the imminent arrival of food– researchers noticed that some animals attempted to ring the buzzer in order to obtain food. The same behaviour can be observed in other species. In rats, a non-functional lever presented to the animal before receiving food will cause some animals to press the lever, a behaviour known as "sign tracking". Other animals go for the food distributor (goal tracking), or alternate between these two behaviors. These individual approach styles correlate with other phenotypes—the sign tracker animals have poor attention control, a propensity to addiction and a greater probability of drug relapse. These individual styles of behaviour are observed in other species, including humans, in which sign tracking is linked to obesity. Animals who engage in sign tracking have several neurological differences, in particular to their dopaminergic reward system (D2 and D3 receptors, DAT). Although acetylcholine is a neurotransmitter whose function is related to attention, this neurotransmitter exerts some control on the dopaminergic system and may be involved in sign-tracking behaviour. Only a few studies have examined the role of acetylcholine in the individual style behaviour. Since sign tracker rats are known to show attentional deficits that are acetylcholine dependent, we suspect a weaker control by the acetylcholine system. Acetylcholine is largely overlooked; its study is a fundamental interest since it is known to control factors of reward. ***My innovative research program aims at better understanding the role of acetylcholine in reward valuation and individual differences in approach style. To define the acetylcholine role in the individual approach style, three specific objectives are proposed. 1- We will identify the role of the differents parts of the cholinergic system on the individual approach style by lesioning 3 different acetylcholine areas of the brain (top-down attention, bottom-up attention and reward system). 2- We will evaluate the electrophysiological (ERP) differences according to the individual approach style. 3- We will quantify the neuroanatomical differences from the sign tracker and goal tracker animals, in the three regions aforementioned in objective 1. Overall, these findings will provide new knowledge about the origins of the individual approach style and are especially important since these animals also show deficits in attention, vulnerability to drug dependence and greater susceptibility to relapse. The role of acetylcholine in the individual approach style is a great new vista leading to a better understanding of addiction, attention control and their comorbidity.**