Frazier-Cierpial L L, Brunjes P C
Department of Psychology, University of Virginia, Charlottesville 22903.
Brain Res Dev Brain Res. 1989 May 1;47(1):129-36. doi: 10.1016/0165-3806(89)90115-6.
Unilateral naris closure in rat pups on the day after birth (P1) results in a substantial loss of synaptic targets for the late developing granule cell population, suggesting granule cell differentiation may be altered. However, dramatic reductions in granule cell numbers also occur in deprived bulbs. A loss of 'competitors' may therefore balance losses in synaptic availability. The issue was quantitatively addressed by analyzing granule cell dendritic development in both sham-operated and unilaterally deprived pups. The period between P10 and P30 was marked by significant developmental increases in dendritic height, length and numbers of branches in control subjects. Continued growth was virtually confined to the most distal processes. Spine number and density also increased, but subsequently decreased in all by sixth-order processes. Growth curves for normal and deprived conditions were virtually identical at all ages suggesting that deprivation-induced changes do not involve alterations in initial phases of granule cell dendritic elaboration.
出生后第一天（P1）对新生大鼠幼崽进行单侧鼻孔封闭，会导致发育较晚的颗粒细胞群体的突触靶点大量丧失，这表明颗粒细胞分化可能会发生改变。然而，在剥夺侧的嗅球中，颗粒细胞数量也会显著减少。因此，“竞争者”的丧失可能会平衡突触可利用性的损失。通过分析假手术组和单侧剥夺组幼崽的颗粒细胞树突发育情况，对这一问题进行了定量研究。在P10到P30期间，对照组的树突高度、长度和分支数量有显著的发育性增加。持续生长几乎局限于最远端的突起。棘突数量和密度也增加了，但随后在所有六级突起中均减少。正常和剥夺条件下的生长曲线在所有年龄段几乎相同，这表明剥夺诱导的变化并不涉及颗粒细胞树突细化初始阶段的改变。
