NEURAL MECHANISMS OF VISION

各种各样的实验表明谷氨酸受体是重要的 视觉皮层的感官可塑性。的信号进行 感觉依赖的可塑性是通过电传递到大脑皮层的 活动，在皮层释放谷氨酸。谷氨酸激活 NMDA、AMPA/红藻氨酸和代谢型谷氨酸受体。的重要性 有证据表明，（i）NMDA受体拮抗剂 受体降低可塑性;（ii）NMDA受体最丰富， 感觉依赖可塑性的临界期的峰值;（iii） NMDA受体对视觉反应的功能性贡献 在关键期内减少;及（iv）在黑暗中饲养 延迟了NMDA对视觉反应的贡献的变化， 就像它推迟了感觉依赖可塑性中的其他事件一样。这 提案将评估NMDA功能的机制， 感受器在感觉依赖的关键时期发生变化 可塑性。对代谢型谷氨酸受体知之甚少， 在关键时期他们的影响力如何变化。这项建议 将评估代谢型谷氨酸受体 对视觉反应的影响，以及这是如何在 发展代谢型谷氨酸受体影响K+通道、Ca++ 渠道和第二信使。该提案还将对行动进行检验 第二信使cAMP上的代谢型谷氨酸受体： 代谢型受体激活它，无论激活后， 关键期的时间进程，以及激活如何受到影响 在黑暗中成长

A variety of experiments suggest that glutamate receptors are important in sensory-dependent plasticity in the visual cortex. The signals for sensory-dependent plasticity are carried to the cortex by electrical activity, which releases glutamate in the cortex. Glutamate activates NMDA, AMPA/kainate and metabotropic glutamate receptors. The importance of NMDA receptors is suggested by evidence that (i) antagonists to NMDA receptors reduce plasticity; (ii) NMDA receptors are most abundant at the peak of the critical period for sensory-dependent plasticity; (iii) the functional contribution of NMDA receptors to the visual response is reduced during the critical period; and (iv) rearing in the dark postpones the change in the NMDA contribution to the visual response, just as it postpones other events in sensory-dependent plasticity. This proposal will evaluate the mechanisms by which the function of NMDA receptors changes during the critical period for sensory-dependent plasticity. Less is known about metabotropic glutamate receptors, and how their influence changes during the critical period. This proposal will evaluate the contribution that metabotropic glutamate receptors make to the visual response, and how this is altered during development. Metabotropic glutamate receptors affect K+ channels, Ca++ channels, and second messengers. The proposal will also test the action of metabotropic glutamate receptors on the second messenger cAMP: which metabotropic receptor activates it, whether the activation follows the time course of the critical period, and how the activation is affected by rearing in the dark.