NEURAL BASIS OF MOTIVATED BEHAVIORS

我们研究的长期目标是了解 复杂动机行为的可塑性。为了实现这个目标，我们建议 来研究负责的电路和神经机制 在一个简单的模型系统中产生摄食行为，海兔 卡里福尼卡。这项研究将利用综合的跨学科 结合了解剖学、免疫细胞化学、 电生理和生化技术与行为 分析。我们将调查的主要问题涉及到 利用相同的神经元元素和相同的肌肉 在执行各种协调行为时，每种协调行为都可能有所不同 在强度和速度上。我们建议可以通过以下方式实现这一点 有两大类机制。第一，包括创造 不同功能的马达电路，通过激活不同的 不同行为的运动神经元组合，以及不同行为的变化 在这些情况下的运动神经元的放电模式 行为反应的强度或频率的变化。这个 第二组假设的机制通过改变比例来运行 和调节性共递质(特别是神经肽)的组合 和作用于肌肉的经典递质，从而调整 肌肉的特性，以满足特定的行为需求。一个 包含这两组机制的概念模型将是 经过测试，如果正确，将有助于指导未来对 回路选择和神经调节在动机行为中发挥作用。这些 研究应该有助于理解动机的神经基础 行为及其功能障碍，如流行的精神疾病所见 比如抑郁症和躁狂症。

The long-term goal of our research is to understand the neural basis of plasticity of complex motivated behaviors. Towards this goal, we propose to investigate the circuits and neural mechanisms that are responsible for the generation of feeding behavior in a simple model system, Aplysia californica. This research will utilize an integrated interdisciplinary approach that combines anatomical, immunocytochemical, electrophysiological, and biochemical techniques with a behavioral analysis. The major question we will investigate concerns the ability of an organism to utilize the same neuronal elements and the same muscles in executing a variety of coordinated behaviors each of which can vary in their intensity and speed. We propose that this may be achieved by two major groups of mechanisms. The first, consists of creating different functional motor circuits, through activation of different combinations of motorneurons for different behaviors, and of changes of firing patterns of motorneurons in those cases when within a single behavior either the intensity or the frequency of responding change. The second postulated group of mechanisms operate by changing the proportions and combination of modulatory cotransmitters (especially neuropeptides) and classical transmitters acting on the muscle, thus adjusting the properties of the muscle to meet specific behavioral demands. A conceptual model that incorporates both groups of mechanisms will be tested, and if correct, will help guide future studies of the role that circuit selection and neuromodulation play in motivated behaviors. These studies should facilitate understanding of the neural basis of motivated behaviors and of their dysfunction, as seen in prevalent mental illnesses such as depression and mania.