The role of brain neurotransmitters in the control of behaviour

大脑神经递质在行为控制中的作用

• 批准号: RGPIN-2015-05465
• 负责人: Beninger, Richard
• 金额: $ 2.4万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=645148
• 关键词: role; brain; neurotransmitters; control; behaviour

It is widely known that behavior can be modified by rewards (e.g., food, water, safety from danger, sex) but much less is known about the underlying brain mechanisms. Rewards produce incentive learning, i.e., the acquisition, by stimuli that predict reward, of an increased ability to elicit approach and other responses. This form of learning is mediated by the brain neurotransmitter dopamine that is released when reward is received. In the brain of the animal or human that received the reward, released dopamine occupies receptors - fitting into them like a key in a lock - that influence chemical messages inside brain nerve cells, i.e., neurons. These chemical messages are responsible for the growth processes and other chemical changes that underlie incentive learning. Dopamine receptors are of several types, forming two families known as D1- and D2-like receptors. Previous work has identified an important role in incentive learning for the chemical messengers activated by D1-like receptors. More recently, D2-like receptors have been found to influence a different set of chemical messengers but little is known about their possible role in incentive learning. The proposed experiments investigate the possible role of D2-like receptor-linked chemical messengers in incentive learning. Rats will be trained in a task where they normally demonstrate a preference for a place where they have previously received reward. My student trainees and I will use drugs that are known to influence the chemical messengers activated by D2-like receptors and inject them into the body or into the brain of the rats. If these drugs dose-dependently impair reward-related incentive learning, results will implicate D2-like receptor signaling in the mechanisms underlying that learning.****When animals or humans encounter novel places or things, they are initially interesting and often explore but if nothing biologically important happens, these places or things quickly lose their attractiveness and become habituated. Like incentive learning, this is also a form of learning; in this case stimuli that predict no reward lose their ability to elicit approach and other responses. I have termed this for of learning as inverse incentive learning. Very little is known about the chemical mechanisms in the brain that mediate inverse incentive learning but decreases in dopamine seem to be involved. Proposed studies carried out by undergrad and grad student trainees in my lab will evaluate the possible role of D1- and D2-like receptors in inverse incentive learning. ****Unraveling the chemical messenger pathways in the brain that underlie reward-related incentive learning and inverse incentive learning will lead to a better understanding of the working of the brains of animals and humans. By understanding how we learn about our environment we will be better able to adapt more effectively by optimizing utilization of the underlying mechanisms. **

众所周知，行为可以通过奖励来改变（例如，食物、水、远离危险的安全、性），但对潜在的大脑机制知之甚少。 奖励产生激励学习，即，通过预测奖励的刺激获得增强的引起接近和其他反应的能力。 这种形式的学习是由大脑神经递质多巴胺介导的，多巴胺在获得奖励时释放出来。 在接受奖励的动物或人类的大脑中，释放的多巴胺占据受体-就像锁中的钥匙一样适合它们-影响脑神经细胞内的化学信息，即，神经元 这些化学信息负责生长过程和其他化学变化，这些化学变化是激励学习的基础。 多巴胺受体有几种类型，形成两个家族，称为D1和D2样受体。 以前的工作已经确定了一个重要的作用，在激励学习的化学信使激活的D1样受体。 最近，D2样受体被发现影响一组不同的化学信使，但对它们在激励学习中的可能作用知之甚少。 建议的实验研究D2样受体连接的化学信使在激励学习的可能作用。 大鼠将在一项任务中接受训练，在该任务中，它们通常表现出对它们先前获得奖励的地方的偏好。 我和我的学生学员将使用已知的药物来影响由D2样受体激活的化学信使，并将它们注射到老鼠的身体或大脑中。 如果这些药物剂量依赖性地损害奖励相关的激励学习，结果将涉及D2样受体信号传导的机制，学习。当动物或人类遇到新的地方或事物时，它们最初是有趣的，经常探索，但如果没有生物学上重要的事情发生，这些地方或事物很快就会失去吸引力并变得习惯。 与激励学习一样，这也是一种学习形式;在这种情况下，预测没有奖励的刺激失去了引发接近和其他反应的能力。 我把这种学习方式称为反向激励学习. 关于大脑中介导反向激励学习的化学机制知之甚少，但多巴胺的减少似乎与此有关。 在我的实验室中，本科生和格拉德生受训者进行的拟议研究将评估D1和D2样受体在反向激励学习中的可能作用。* 解开大脑中的化学信使通路，这些通路是奖励相关激励学习和反向激励学习的基础，这将有助于更好地理解动物和人类大脑的工作。 通过了解我们如何了解我们的环境，我们将能够更好地适应更有效地通过优化利用底层机制。 **