Kolb Bryan, Gorny Grazyna, Söderpalm Anna H V, Robinson Terry E
Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, T1K 3M4 Canada.
Synapse. 2003 Jun 1;48(3):149-53. doi: 10.1002/syn.10196.
Complex housing has been used widely as a model of experience-dependent change. Animals housed in complex environments typically show synaptogenesis throughout the sensory and motor cortex as well as the striatum and hippocampus, and thus it is generally assumed that such changes are likely to be found throughout the cerebrum. The purpose of the present study was to determine whether persistent alterations of dendritic morphology would be found in two regions that had previously not been examined, namely, the medial prefrontal region (Cg3) and nucleus accumbens (NAcc). The results show that housing female rats in complex environments for 3.5 months increased dendritic arborization on medium spiny neurons in the NAcc and on pyramidal cells in the somatosensory cortex (Par 1), but not in Cg3. Environmental complexity increased spine density in all three areas, however. The failure to find increased dendritic length or branching in Cg3 was unexpected. Thus, the data suggest that complex housing may not engage prefrontal neurons in the same manner as neurons in sensory or motor areas. It appears that complex housing may not produce generalized changes in cerebral morphology. The data further suggest that it is prudent to measure both dendritic length and spine density in studies of experience-dependent effects on synaptic plasticity.
复杂居住环境已被广泛用作经验依赖性变化的模型。饲养在复杂环境中的动物通常在整个感觉和运动皮层以及纹状体和海马体中表现出突触形成，因此一般认为这种变化可能在整个大脑中都能发现。本研究的目的是确定在两个先前未被检查的区域，即内侧前额叶区域（Cg3）和伏隔核（NAcc）中是否会发现树突形态的持续改变。结果表明，将雌性大鼠饲养在复杂环境中3.5个月会增加伏隔核中中等棘状神经元以及体感皮层（Par 1）中锥体细胞的树突分支，但在Cg3中则不会。然而，环境复杂性增加了所有三个区域的棘密度。在Cg3中未发现树突长度或分支增加是出乎意料的。因此，数据表明复杂居住环境可能不会以与感觉或运动区域中的神经元相同的方式影响前额叶神经元。看来复杂居住环境可能不会在大脑形态上产生普遍变化。数据进一步表明，在经验依赖性对突触可塑性影响的研究中，同时测量树突长度和棘密度是谨慎的做法。
