Mitchell Donald E, Sengpiel Frank, Hamilton David C, Schwarzkopf D Samuel, Kennie Jan
Department of Psychology, Dalhousie University, Halifax, NS, Canada.
J Vis. 2011 Jun 16;11(7):13. doi: 10.1167/11.7.13.
Short daily periods of binocular exposure (BE) can offset longer single daily episodes of monocular exposure (ME) to prevent the development of deprivation amblyopia. To determine whether the outcome depended upon an absolute daily amount of BE or its proportion of the daily visual exposure, daily mixed visual input of 3 different durations (3.5, 7, or 12 h) was imposed on 3 cohorts of kittens. Measurements of the visual acuity of the deprived eye at the end of mixed daily visual input revealed that the acuity of the deprived eye developed to normal values so long as the proportion of the total exposure that was binocular was 30% or more. By contrast, the development of functional ocular dominance domains in V1 revealed by optical imaging suggests that normal domains emerge with a fixed amount of daily binocular exposure. The latter result is consistent with the effects of any daily period of ME, or BE, or both, effectively saturating with a small dose so that the effects of ME of any length can be offset by a short period of BE. The different result for vision may reflect neural events at higher and/or multiple levels in the visual pathway.
每天短时间的双眼暴露（BE）可以抵消较长时间的单眼暴露（ME），以防止剥夺性弱视的发生。为了确定结果是否取决于每天BE的绝对量或其在每日视觉暴露中的比例，对三组小猫施加了三种不同持续时间（3.5、7或12小时）的每日混合视觉输入。在每日混合视觉输入结束时对剥夺眼视力的测量表明，只要双眼暴露在总暴露中的比例为30%或更高，剥夺眼的视力就会发展到正常水平。相比之下，光学成像显示的V1中功能性眼优势域的发展表明，正常的眼优势域是在固定的每日双眼暴露量下出现的。后一个结果与任何每日ME期、BE期或两者的影响一致，即小剂量有效地饱和，因此任何长度的ME的影响都可以通过短时间的BE来抵消。视觉方面的不同结果可能反映了视觉通路中更高和/或多个水平的神经事件。
