The role of telencephalic NMDA receptors in avoidance learning in goldfish (Carassius auratus).

Studies with goldfish (Carassius auratus) have suggested that N-methyl-D-aspartate (NMDA) receptors are concentrated most densely in the telencephalon, a simple structure homologous to the limbic structure of higher vertebrates. The present study investigated the amnestic effects of microinjections of the NMDA receptor antagonist D(-)-2-amino-5-phosphonopentanoic acid (D-AP5) to the goldfish telencephalon on avoidance conditioning. Results showed that microinjections of D-AP5 before training impaired avoidance learning at doses that did not impair performance processes. High-performance liquid chromatography measurements showed that D-AP5 was detected only in the telencephalon following microinjections. Thus, D-AP5 impaired avoidance learning through its interaction with telencephalic NMDA receptors in goldfish. Furthermore, microinjections of D-AP5 to the goldfish telencephalon immediately following training did not impair memory consolidation of avoidance conditioning.

对金鱼（Carassius auratus）的研究表明，N - 甲基 - D - 天冬氨酸（NMDA）受体在端脑最为密集，端脑是一种与高等脊椎动物边缘结构同源的简单结构。本研究探讨了将NMDA受体拮抗剂D(-)-2 - 氨基 - 5 - 膦酰基戊酸（D - AP5）微量注射到金鱼端脑对回避条件反射的遗忘作用。结果显示，在训练前微量注射D - AP5，在不损害操作过程的剂量下会损害回避学习。高效液相色谱测量表明，微量注射后仅在端脑检测到D - AP5。因此，D - AP5通过与金鱼端脑的NMDA受体相互作用损害了回避学习。此外，在训练后立即将D - AP5微量注射到金鱼端脑并没有损害回避条件反射的记忆巩固。