Department of Animal Biology and Ecology, University of Cagliari Cagliari, Italy.
Department of Animal Biology and Ecology, University of Cagliari Cagliari, Italy ; "G.Minardi" Laboratory of Cognitive Neuroscience, Department of Chemistry and Pharmacy, University of Sassari Sassari, Italy.
Front Neuroanat. 2014 Oct 2;8:110. doi: 10.3389/fnana.2014.00110. eCollection 2014.
Units of dendritic branches called dendritic spines represent more than simply decorative appendages of the neuron and actively participate in integrative functions of "spinous" nerve cells thereby contributing to the general phenomenon of synaptic plasticity. In animal models of drug addiction, spines are profoundly affected by treatments with drugs of abuse and represent important sub cellular markers which interfere deeply into the physiology of the neuron thereby providing an example of the burgeoning and rapidly increasing interest in "structural plasticity". Medium Spiny Neurons (MSNs) of the Nucleus Accumbens (Nacc) show a reduced number of dendritic spines and a decrease in TH-positive terminals upon withdrawal from opiates, cannabinoids and alcohol. The reduction is localized "strictly" to second order dendritic branches where dopamine (DA)-containing terminals, impinging upon spines, make synaptic contacts. In addition, long-thin spines seems preferentially affected raising the possibility that cellular learning of these neurons may be selectively hampered. These findings suggest that dendritic spines are affected by drugs widely abused by humans and provide yet another example of drug-induced aberrant neural plasticity with marked reflections on the physiology of synapses, system structural organization, and neuronal circuitry remodeling.
被称为树突棘的树突分支单位不仅仅代表神经元的简单装饰附属物，它们还积极参与“棘突”神经细胞的整合功能，从而促进突触可塑性的普遍现象。在药物成瘾的动物模型中，刺突受到滥用药物治疗的深刻影响，并且是重要的亚细胞标志物，它们深入干扰神经元的生理学，从而为“结构可塑性”的新兴和快速增长的兴趣提供了一个例子。伏隔核（Nacc）中的中脑导水管周围灰质（MSNs）在戒断阿片类药物、大麻素和酒精后表现出树突棘数量减少和 TH 阳性终末减少。这种减少是“严格”局限于第二级树突分支的，多巴胺（DA）含有终末的地方，影响树突棘，进行突触接触。此外，长而细的棘突似乎更容易受到影响，这增加了这些神经元的细胞学习可能会被选择性阻碍的可能性。这些发现表明，树突棘受到人类广泛滥用的药物的影响，并提供了另一个药物引起的异常神经可塑性的例子，对突触生理学、系统结构组织和神经元电路重塑有明显的反映。
