Martijena I D, Arce A
Cátedra de Química Biológica, Facultad de Ciencias Exactas, Fisicas y Naturales, Universidad Nacional de Córdoba, Argentina.
Can J Physiol Pharmacol. 1994 Mar;72(3):233-7. doi: 10.1139/y94-036.
One-day-old chicks were exposed to a one-time passive avoidance learning task. After chicks peak a bead dipped in a bitter-tasting liquid, they learn to stop pecking the bead. Radioligand binding analysis of [3H]flunitrazepam was performed on crude synaptosomal membranes from forebrains, at 10, 30, and 60 min post-training. Water-trained chicks (control) pecked a bead dipped in water, and they did not learn to stop pecking the bead. The water control was complemented with a methyl anthranilate fed control chick to demonstrate that taste per se does not affect the [3H]flunitrazepam binding. At 30 min in relation to 10 min post-training, the Bmax increased 31% in water-trained chicks and 56% in taste-trained chicks, with Bmax of the taste-trained chicks reaching a value 22% higher than that in water-trained chicks. The difference, attributable to the learning, disappeared at 60 min post-training, and at all times the affinity remained unchanged. The Bmax increase in water-trained chicks might be attributable to psychological stress accompanying the task and the Bmax increase in taste-trained chicks attributable to the learning in addition to the stress accompanying the task. The results suggest that the receptor increase associated with learning is involved in early stages of memory formation.
将一日龄雏鸡暴露于一次性被动回避学习任务中。雏鸡啄食蘸有苦味液体的珠子达到峰值后，它们学会停止啄食珠子。在训练后10分钟、30分钟和60分钟，对来自前脑的粗制突触体膜进行[3H]氟硝西泮的放射性配体结合分析。接受水训练的雏鸡（对照组）啄食蘸有水的珠子，并且它们没有学会停止啄食珠子。用水杨酸甲酯喂养对照雏鸡作为水对照组，以证明味觉本身不会影响[3H]氟硝西泮结合。与训练后10分钟相比，在30分钟时，接受水训练的雏鸡的最大结合容量（Bmax）增加了31%，接受味觉训练的雏鸡增加了56%，接受味觉训练的雏鸡的Bmax值比接受水训练的雏鸡高22%。这种因学习导致的差异在训练后60分钟消失，并且在所有时间亲和力均保持不变。接受水训练的雏鸡的Bmax增加可能归因于任务伴随的心理应激，而接受味觉训练的雏鸡的Bmax增加除了任务伴随的应激外还归因于学习。结果表明，与学习相关的受体增加参与了记忆形成的早期阶段。
