Shaffery J P, Oksenberg A, Marks G A, Speciale S G, Mihailoff G, Roffwarg H P
Dept. of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson 39216-4505, USA.
Sleep. 1998 Dec 15;21(8):837-45. doi: 10.1093/sleep/21.8.837.
In this study, we test the hypothesis that when REM-state activation (which impinges upon all lateral geniculate nucleus laminae irrespective of stimulating eye) is deprived, the monocular segment (MS) that is cut off from visual input and also deprived of REM-state activation will exhibit smaller cells, owing to the loss of extrinsic as well as intrinsic activation.
We carried out a study comparing soma sizes in the MSs of kittens subjected to monocular deprivation (MD) + REM deprivation (RD) to two age-matched nonRD groups, MD ONLYs and MD MOMS (MD kittens living in their home cages).
Perikaryal outlines of 100 cells in each of the bilateral MSs were measured. As predicted, mean cell size in the MS connected to the patched eye of MD + RD kittens, but in neither of the control groups, was significantly smaller than in the MS afferented by the nonpatched eye. One-way ANOVAs comparing MS cell-size means from the same sides across groups were also significant, but the two MSs showed different results on post hoc tests. The ordering of MS cell-size means correlated significantly with a measure that aggregates the sources of activation reaching a particular MS and their durations.
These results reveal that removal of REM-state activation during CNS development amplifies the plasticity processes generated when normal visual afferentation to central visual areas is interrupted. Our findings in the MS of the LGN indicate that during the usual operation of REM sleep, central visual-sensory sites receive intrinsic activation that, in the visual system, is additive and complementary to the stimulation obtained from extrinsic sources. In the course of early development, normative symmetrical activation of central visual areas during REM sleep may counterbalance plasticity changes caused either by absent or aberrant sensory stimulation.
在本研究中，我们检验了以下假设：当快速眼动（REM）状态激活被剥夺时（这种激活作用于所有外侧膝状体核层，而不论刺激的是哪只眼睛），与视觉输入切断联系且也被剥夺REM状态激活的单眼节段（MS），由于外在及内在激活的丧失，将呈现出更小的细胞。
我们开展了一项研究，将接受单眼剥夺（MD）+快速眼动剥夺（RD）的小猫的MS中的体细胞大小，与两个年龄匹配的非快速眼动剥夺组进行比较，即仅单眼剥夺组和单眼剥夺并与母亲同笼组（生活在其家笼中的单眼剥夺小猫）。
测量了双侧MS中每组100个细胞的核周轮廓。如预期的那样，MD+RD小猫被遮盖眼睛所连接的MS中的平均细胞大小，在两个对照组中均未出现这种情况，显著小于未被遮盖眼睛传入的MS中的平均细胞大小。比较不同组同侧MS细胞大小均值的单因素方差分析也具有显著性，但两个MS在事后检验中显示出不同的结果。MS细胞大小均值的排序与一项汇总到达特定MS的激活源及其持续时间的指标显著相关。
这些结果表明，在中枢神经系统发育过程中去除REM状态激活会放大当正常视觉传入至中枢视觉区域被中断时产生的可塑性过程。我们在外侧膝状体核MS中的发现表明，在REM睡眠的正常运作过程中，中枢视觉感觉位点会接收到内在激活，在视觉系统中，这种激活与从外在源获得的刺激相加且互补。在早期发育过程中，REM睡眠期间中枢视觉区域的规范性对称激活可能会抵消由缺失或异常感觉刺激引起的可塑性变化。
