Boothe R G, Greenough W T, Lund J S, Wrege K
J Comp Neurol. 1979 Aug 1;186(3):473-89. doi: 10.1002/cne.901860310.
In a previous Golgi study (Lund et al., '77) which examined the development of the macaque monkey striate cortex (area 17) it was observed that the dendrites of neurons within the visual cortex show a marked increase in the number of spines on their surface during the first eight weeks of postnatal life. The qualitative observation was also made that all neurons then showed a marked decrease in spine numbers by the time the animal was adult. Since these spines are known to be sites of synaptic contact, changes in their numbers may reflect changes in synapse populations on these neurons. This study examines quantitatively spine frequency and total dendritic development of Golgi impregnated neurons in monkeys ranging in age from 145 days gestation to adult. Four cell types were studied: spiny stellate neurons from laminae IVCalpha and IVCbeta and pyramidal neurons with soma in either lamina IIIB or upper lamina VI. After consideration of possible sources of variation in spine numbers several conclusions are made: (1) Dendritic spine development appears to be a tightly controlled process both in terms of actual numbers of spines on a neuron at any one age and in the rate of change of spine frequency. (2) The neurons populations examined all show a gradual increase in spine numbers up to eight weeks of age. (3) At least two different trends are found in spine population maturation after the eight week point: (A)-the spine population may remain constant at the eight week level for same period of time or (B)-there may be a rapid decline in spine numbers following the eight week peak. (4) There is a suggestion that those neurons associated with direct input, or early stages in the relays, from the parvocellular geniculate laminae show trend B, while those associated with magnocellular input, or later order combined relays within the cortex, show trend A. (5) Different parts of a single pyramidal neuron dendrite may show either trend A or trend B, depending on the lamina location of the dendritic segment considered. (6) All neurons show spine population decreases between nine months of age and adult (5-7 years) suggesting continuing long term maturational changes.
在之前一项对猕猴纹状皮层（17区）发育进行研究的高尔基染色研究（伦德等人，1977年）中，观察到视皮层内神经元的树突在出生后前八周其表面的棘突数量显著增加。还进行了定性观察，即到动物成年时，所有神经元的棘突数量都显著减少。由于已知这些棘突是突触接触的部位，其数量的变化可能反映了这些神经元上突触群体的变化。本研究定量考察了从妊娠145天到成年的猴子中，经高尔基染色的神经元的棘突频率和树突的整体发育情况。研究了四种细胞类型：IVCalpha层和IVCbeta层的棘状星形神经元以及胞体位于IIIB层或VI层上部的锥体神经元。在考虑了棘突数量可能的变化来源后，得出了几个结论：（1）树突棘的发育似乎是一个受到严格控制的过程，这体现在任一年龄时单个神经元上棘突的实际数量以及棘突频率的变化速率方面。（2）所研究的神经元群体在八周龄之前棘突数量都呈逐渐增加趋势。（3）在八周龄之后的棘突群体成熟过程中至少发现了两种不同趋势：（A）棘突群体可能在八周龄水平保持一段时间不变，或者（B）在八周龄达到峰值后棘突数量可能迅速下降。（4）有迹象表明，那些与来自小细胞膝状体层的直接输入或中继早期阶段相关的神经元呈现趋势B，而那些与大细胞输入或皮层内更高阶联合中继相关的神经元呈现趋势A。（5）单个锥体神经元树突的不同部分可能呈现趋势A或趋势B，这取决于所考虑的树突段在层中的位置。（6）所有神经元在九个月龄到成年（5 - 7岁）之间棘突群体数量都减少，这表明存在持续的长期成熟变化。
