Expression of "Imprinting"memory in chick brain

1.视觉辨别任务后记忆内容形成的行为学研究新孵化的雏鸡学会通过经验辨别什么是可以吃的，什么是不能吃的。在讨厌的物体上啄食的单一经历会导致长期记忆的形成；这种任务被称为“一次尝试被动回避任务”。对任务完成后形成的雏鸡知觉图谱的详细分析表明，雏鸡分别加工颜色和形状，前者退化早于后者。雏鸡脑内视觉图像关联区表达的单单位分析我们发展了一种技术，可以从行为自由的清醒雏鸡的大脑(视觉关联区和基底节)记录单个神经元的活动数小时。部分神经元在被动回避记忆形成后立即出现特征的连贯爆发。基底节突触可塑性的神经生理学研究长时程增强和突触汇聚输入抑制的同时诱导。基底节(LPO区)被认为是储存被动回避记忆的大脑区域，用于选择性地执行啄食行为。脑片LPO神经元的场电位和全细胞膜片记录显示兴奋性输入的汇聚。同时的强直刺激导致“中央纹状体”输入的LTP和“AMGDALO-纹状体”输入的伴随LTP。

1. Behavioral study on the memory contents formed after visual discrimination taskNewly hatched chicks learn to discriminate what is edible and what is not by experiences. Single experience of pecking at a aversive object results in a formation of long-term memory ; a task refered to as "one-trial passive avoidance task." Detailed analysis of chick perceptual map formed after this task revealed that chicks process "color" and "shape" separately, the former deteriorates earlier than the latter.2. Single-unit analysis on the expression of visual images in association area of chick brainWe have developed a technique, where activity of single neurons can be recorded for hours from brain (visual association area and basal ganglion) of freely-behaving awake chicks. Some neurons revealed characteristic coherent bursts immediately after the formation of the passive avoidance memory.3. Neurophysiological study on the synaptic plasticity in basal gangion ; concurrent induction of long-term potentiation and depression of converging synaptic inputs.The basal gangion (area LPO) is assumed the brain region where the passive avoidance memory is stored for selective execution of pecking behavior. Field potential and whole cell patch recording from the LPO neurons in slices revealed convergence of excitatory inputs. Coincident tetanic stimuli caused a LTP in "cotrico-striatal" inputs and a concomittant LTD in the "amgdalo-striatal" inputs.