AVIAN AUDITORY BRAINSTEM SYNAPSES AND INTENSITY CODING

短期突触可塑性对其所在的神经回路的功能有着深远的影响。Nelson实验室先前的工作使用定量（参数化）方法描述了大鼠视觉皮层的短期可塑性，使用在生理频率范围内传递的诱发刺激序列。通过对大鼠大脑皮层切片2/3层的非锥体神经元进行全细胞电压钳记录，将先前对锥体细胞获得的结果扩展到抑制性中间神经元抑制性输入的短期可塑性表征。这些抑制性中间神经元将在生理学和形态学上进行表征和鉴定。我们的目标是：1)通过细胞外或细胞内突触前刺激来表征诱导多能干细胞的神经元间突触可塑性；2)确定突触可塑性是否因突触前或突触后神经元的中间亚型而有差异表达；3)研究乙酰胆碱等神经调节剂是否能改变神经元间突触的可塑性。通过研究胆碱能对皮层突触可塑性的调节，这些结果可能对大脑的行为和认知功能以及可能与胆碱能功能障碍相关的神经系统疾病（如阿尔茨海默病）具有指导意义。

Short-term synaptic plasticity has a profound effect on the function of the neural circuit in which it is embedded. Previous work in the Nelson lab has characterized the short-term plasticity in the rat visual cortex using a quantitative (parametric) method, using trains of evoked stimuli delivered over a range of physiological frequencies. extend results previously obtained for pyramidal cells to a characterization of the short-term plasticity of inhibitory inputs to inhibitory interneurons by making whole-cell voltage-clamp recordings of nonpyramidal neurons in layers 2/3 in slices of rat neocortex. These inhibitory interneurons will be characterized and identified physiologically and morphologically. Our goals are: 1) Characterize the interneuron-interneuron synaptic plasticity of evoked IPSCs by extracellular or intracellular presynaptic stimulation; 2) Determine if the synaptic plasticity is differentially expressed depending on the interneuron subtype of the presynaptic or postsynaptic neuron; and 3) Investigate whether the interneuron-interneuron synaptic plasticity can be modified by neuro-modulatory agents such as acetylcholine. By investigating the cholinergic modulation of cortical synaptic plasticity, these results may have implications for behavioral and cognitive brain function, and the neurological disorders, such as Alzheimer's disease, which may be related cholinergic dysfunction.