Hata Y, Ohshima M, Ichisaka S, Wakita M, Fukuda M, Tsumoto T
Department of Neurophysiology, Biomedical Research Center, Osaka University Medical School, 2-2 Yamadaoka, Suita,Osaka 565-0871, Japan.
J Neurosci. 2000 Feb 1;20(3):RC57. doi: 10.1523/JNEUROSCI.20-03-j0002.2000.
Segregation and stabilization of thalamocortical afferents to eye-specific patches, so-called "ocular dominance (OD) columns," in visual cortex are hypothesized to be based on activity-dependent competition for trophic factors such as brain-derived neurotrophic factor (BDNF) between afferents representing the two eyes during the critical period of postnatal development. To test this hypothesis we observed effects of an intracortical infusion of BDNF on OD columns in monocularly deprived kittens and also compared effects between normal kittens and adult cats. BDNF had a hypertrophic action on afferents irrespective of visual inputs so that it desegregated OD columns in the visual cortex of deprived and normal kittens, but this action was not seen in the adults, substantiating its hypothesized trophic role in plasticity of OD columns in the developing visual cortex.
丘脑皮质传入纤维向视觉皮层中所谓的“眼优势（OD）柱”的眼特异性斑块的分离和稳定，被认为是基于出生后发育关键期内代表两只眼睛的传入纤维之间对诸如脑源性神经营养因子（BDNF）等营养因子的活动依赖性竞争。为了验证这一假设，我们观察了皮层内注入BDNF对单眼剥夺小猫OD柱的影响，并比较了正常小猫和成年猫之间的影响。BDNF对传入纤维具有肥大作用，与视觉输入无关，因此它使剥夺和正常小猫视觉皮层中的OD柱分离，但在成年猫中未观察到这种作用，证实了其在发育中的视觉皮层OD柱可塑性中假设的营养作用。
