Neural Substrates of Learning

人类和动物每天学习的许多东西都是基于两个事件之间的简单联系。人类学会了避免热炉子;门铃响表明有访客，猫学会了接近开罐器的声音，期待着收到食物，这只是几个例子。 这些事件通过5个主要的模态特定通路（视觉、听觉、躯体感觉、嗅觉和味觉）被带入神经系统。每一种方式都记录了非常不同的刺激，并具有独特的神经输入系统。跨不同模态的学习是否需要与输入类型相同数量的神经回路？也许有位于中央的神经回路取决于正在处理的全局信息的类型，而不是个人的感觉模态？如果要学习类似的运动反应，则可以使用相同的神经学习回路。简单关联的行为参数，即，经典条件作用，即一个刺激物预测另一个刺激物的发生，已经得到很好的研究。两种特定类型的经典条件反射，眨眼和恐惧条件反射的音调刺激的神经基板，已被验证从输入到输出的使用病变，解剖跟踪和神经元记录的研究。眨眼条件反射类似于肢体屈曲条件反射。当使用来自样本模态的线索时，类似类型的经典条件反射的神经元学习回路有多相似？当使用来自不同模态的线索时，这些不同的输入是否会汇聚到一个共同的回路上，以实现特定运动反应的经典条件反射？所提出的研究的目的是双重的：首先，映射的神经基板，通过测量葡萄糖能量代谢在整个大脑中，一个简单的经典的条件反射范例，肢体屈曲使用常用的纯音刺激。将结果与已知的眨眼条件反射电路进行比较。第二，利用视觉和躯体感觉刺激的其他方式的线索，映射这种经典条件反射的神经基质。许多人很难仅仅通过一种或另一种感觉方式进行学习。这种类型的研究可以识别这些类型的缺陷被修改的特定大脑区域。

Many things that humans and animals learn everyday are predicated on a simple association between two events. Humans learn to avoid hot stoves; a doorbell ringing indicates visitors, and cats learning to approach to the sound of the can opener in the anticipation of receiving food are just a few examples. These events are brought into the neural system by 5 main modality specific pathways, visual, auditory, somatosensory, olfactory and gustatory. Each one of these modalities records very different stimuli and has a unique neural input system. Does learning across different modalities require the same number of neural circuits as types of input? Perhaps there are centrally located neural circuits depending on the type of global information being processed rather than on the individual sensory modality? If similar motor responses were to be learned the same neural learning circuit might be used. The behavioral parameters of simple associative, i.e., classical conditioning, where one stimulus predicts the occurrence of another stimulus, have been well worked out. The neural substrates underlying two specific types of classical conditioning, eyeblink and fear conditioning to tone stimuli, have been verified from input to output with the use of lesion, anatomical tracing and neuronal recording studies. Eyeblink conditioning is similar to limb flexion conditioning. How similar are the neuronal learning circuits for similar types of classical conditioning when using cues from the sample modality? When using cues from different modalities, do these different inputs converge on a common circuit for classical conditioning of a particular motor response? The aim of the proposed research is two-fold: First, map the neural substrates, through measurement of glucose energy metabolism across the whole brain, for a simple classical conditioning paradigm, limb flexion using the commonly used pure tone stimulus. The results will be compared to the known circuitry for eyeblink conditioning. Second, map the neural substrates of this classical conditioned reflex using cues from additional modalities using visual and somatosensory stimuli. Many humans have difficulty learning solely by presentations made in one sensory modality or another. This type of research may allow for the identification of the specific brain regions where these types of deficits are modified.