Motor Systems Supporting Pavlovian Conditioning

支持巴甫洛夫调节的运动系统

基本信息

批准号：
6772089
负责人：
TERRY J CROW
金额：
$ 29.7万
依托单位：
UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
依托单位国家：
美国
项目类别：
财政年份：
1998
资助国家：
美国
起止时间：
1998-08-01 至 2009-06-30
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): The long-term objective of this research project is to identify the neural circuit that is responsible for the generation of light-elicited ciliary locomotion and reflex-elicited foot contraction; and to understand how Pavlovian conditioning changes synaptic connections between neurons and alters intrinsic cellular excitability in the circuit. The experiments proposed in this grant will provide insights into how a neural circuit can be modified by Pavlovian conditioning to support the generation of two conditioned responses; CS-elicited foot contraction and conditioned inhibition of light-elicited locomotion. To achieve these goals, a multidisciplinary approach to the study of the cellular and synaptic basis of light-elicited ciliary locomotion and foot contraction will be carried out in the marine mollusk Hermissenda; a preparation that has proven useful in biophysical, biochemical, and molecular studies of learning. One primary goal will be to analyze conductances that contribute to the enhanced intrinsic excitability of the interneurons of conditioned animals using voltage-clamp techniques. We will also further identify neurons in the circuit that supports the generation of light-elicited ciliary locomotion and reflex-elicited contraction of the posterior foot. Using isolated nervous systems, intact animals and semi-intact preparations, we will identify the neural elements of the circuit and determine how the properties of the network contribute to the generation of light-elicited ciliary locomotion and reflex-elicited foot contraction. A second major goal is to determine how the circuit supporting locomotion and reflex-elicited foot contraction can be modified by Pavlovian conditioning. We will examine ciliary activation and statocyst-elicited foot contraction in semi-intact preparations while recording from interneurons and pedal motor neurons. Interneurons that receive sensory input from identified photoreceptors and hair cells, and project to cilia-activating and foot contraction pedal motor neurons will be identified and characterized. We will examine synaptic input to polysensory type I interneurons of conditioned animals to determine how Pavlovian conditioning modifies one sensory input, mediated by the conditioned stimulus (CS), without increasing the responsiveness of the type I interneurons to other sensory inputs. This experimental approach will expand our understanding of conditioning in Hermissenda by identifying within the neural circuit supporting the generation of behavior, other potential loci of plasticity produced by conditioning and provide the database for understanding how intrinsic cellular and synaptic modifications specific to one modality can be expressed in a circuit that must also support normal polysensory processing. These studies will help to elucidate general principles underlying the organization of polysensory neural systems generating behavior and their modification by learning.

描述（由申请人提供）：该研究项目的长期目标是确定负责发光的纤毛运动和反射引起的脚部收缩的神经回路；并了解巴夫洛维亚的调节如何改变神经元之间的突触连接，并改变电路中固有的细胞兴奋性。该赠款中提出的实验将提供有关如何通过帕夫洛维亚调节来修改神经回路以支持产生两个条件反应的洞察力； CS引起的脚部收缩和有条件抑制光引起的运动。为了实现这些目标，将在海洋软体动物hermissenda中采取多学科研究的研究。事实证明，这种制剂可用于学习的生物物理，生化和分子学习。一个主要目标是分析使用电压钳技术有助于提高条件动物中神经元的内在兴奋性的电导。我们还将进一步识别电路中的神经元，该神经元支持后脚的光引起的睫状运动和反射浮动的收缩。使用孤立的神经系统，完整的动物和半独立制剂，我们将确定电路的神经元素，并确定网络的性质如何有助于产生光吸收的纤毛运动和反射式散热的脚部收缩。第二个主要目标是确定如何通过帕夫洛维亚调节来修改支持运动和反射引起的脚部收缩的电路。我们将在半独立制剂中检查睫状激活和statocyst引起的脚部收缩，同时记录中间神经元和踏板运动神经元。将鉴定和表征从鉴定的感光体和毛细胞中接收感觉输入的中间神经元，并投影到纤毛激活和脚部收缩踏板运动神经元。我们将检查有条件动物的多通感应I型I类中神经元的突触输入，以确定Pavlovian条件如何修饰由条件刺激（CS）介导的一种感觉输入，而无需增加I型Interneurons对其他感觉输入的反应性。这种实验方法将通过识别支持行为产生的神经电路中的雌激素的条件，通过调节产生的其他潜在可塑性基因座，并提供数据库，以了解如何在一个电路中表达对一种固有的细胞和突触修饰的数据库，从而扩展我们对雌雄同体调节的理解，并提供了数据库。这些研究将有助于阐明多通神经系统组织产生行为及其修饰的基础的一般原则。