Iny Karen, Heynen Arnold J, Sklar Erik, Bear Mark F
Howard Hughes Medical Institute, The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
J Neurosci. 2006 Jul 12;26(28):7368-74. doi: 10.1523/JNEUROSCI.0124-06.2006.
Recent electrophysiological studies of rodent visual cortex suggest that, in addition to deprived-eye depression, monocular deprivation (MD) also shifts ocular dominance by potentiation of open-eye responses. We used computer-based, two-choice discrimination tasks to assess the behavioral significance of these findings in rats. As expected, prolonged MD, from postnatal day 21 until adulthood (>150 d) markedly decreased visual acuity through the deprived eye. However, we also found that the acuity through the nondeprived eye was significantly enhanced compared with normally reared controls. Interestingly, when the deprived eye was opened in adults, there was a gradual but incomplete recovery of acuity in the deprived eye preceded by a loss of the enhanced acuity in the nondeprived eye. These changes were reversed by again reclosing the eye. These findings suggest that the bidirectional changes in visually evoked responses after MD are behaviorally meaningful and that significant plasticity is exhibited well into adulthood.
近期对啮齿动物视觉皮层的电生理研究表明，除了剥夺眼抑制外，单眼剥夺（MD）还通过增强睁眼反应来改变眼优势。我们使用基于计算机的二选一辨别任务来评估这些发现在大鼠中的行为意义。正如预期的那样，从出生后第21天到成年期（>150天）的长期MD显著降低了通过剥夺眼的视敏度。然而，我们还发现，与正常饲养的对照组相比，通过未剥夺眼的视敏度显著提高。有趣的是，当成年后打开剥夺眼时，剥夺眼的视敏度会逐渐但不完全恢复，在此之前未剥夺眼增强的视敏度会丧失。再次闭上该眼后，这些变化会逆转。这些发现表明，MD后视觉诱发反应的双向变化在行为上是有意义的，并且在成年期仍表现出显著的可塑性。
